Autotrophic denitrification chamber and calcium reactor

ABSTRACT

The present invention describes novel biological systems for efficiently reducing nitrate levels and otherwise conditioning aquarium water and water in similar environments.

RELATED APPLICATIONS

This is a division of application Ser. No. 10/673,634, filed Sep. 30,2003 now U.S. Pat. No. 7,025,883, which is incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to apparati and methods for conditioningwater in aquariums and similar environments for holding fish,invertebrates, and other aquatic creatures, including coral. Morespecifically the invention relates to denitration reactor systems andmethods for removing nitrates and otherwise conditioning water foraquatic purposes in fresh water, brackish water and salt waterapplications.

BACKGROUND

The accumulation of nitrates is a major problem in both salt and freshwater aquariums and similar aquatic environments. Nitrates build uprapidly in these environments due to fish waste and the regular additionof food, which contains nitrogenous compounds. At high enoughconcentrations, nitrates are noxious to aquatic life. To address thisproblem, often polluted water from aquariums is replaced with new waterfrequently in order to maintain a healthy aquarium. The dumping ofnitrate polluted water into the environment furthers the nitratepollution of water supplies worldwide. This water changing is timeconsuming and may also be expensive to both aquatic hobbyists andcommercial aquariums alike, especially if the aquarium is a salt wateraquarium that is not in close proximity to the ocean, or other sourcesof unpolluted aquarium water.

Various methods, other than water changes, are known in the art forremoving nitrates from aquariums. One common method is the use ofprotein skimmers to eliminate nitrogenous compounds before they aretransformed into nitrates. Protein skimmers are constructed in a tube ortower having a collection cup at the top. These skimmers work byinjecting massive amounts of very fine air bubbles into the tube. Therising air bubbles act as a lift in the tube, allowing the undesirablenitrogenous compounds to attach to the bubbles and rise to the surface,where they are captured in the collection cup and disposed of.

Another method involves reducing nitrates using bacteria. Examples ofsuch systems are described in U.S. Pat. No. 4,995,980, to Jaubert; anarticle entitled “Nitrates Elimination by Autotrophic Denitration onSulfur,” by Christophe Soler; and an article by Marck Langouet,entitled, “The Autotrophic Denitration on Sulfur What's the Status?.”

SUMMARY OF THE INVENTION

It is an object of the present invention to provide improved methods andsystems for conditioning water in aquariums and similar environments.

The present invention includes novel biological systems and methods forefficiently reducing nitrate levels and otherwise conditioning aquariumwater and water in similar environments. The methods and systems of thepresent invention maintain a healthy and efficient aerobic bacteriaculture, reduce ammonia in the water to nitrite and nitrite to nitratein an aerobic process, reduce oxygen in the water and generate CO₂before the water is treated by anaerobic bacterial, maintain a healthyand efficient anaerobic bacteria culture, insure that a sufficient foodsupply is maintained for the bacteria culture, efficiently reducenitrates to acceptable levels, control the pH to within safe levels, addhealthy minerals to the water, and reduce odors caused by the productionof hydrogen sulfide gas formed in the autotrophic denitration process.The systems of the present invention are relatively light in weightrelative to the size of the aquarium or similar closed environment ofwater, are easy to use, need little maintenance, and are unlikely toclog or overflow.

One embodiment of the invention is directed to a process forconditioning aquarium water or other closed environments for aquaticlife. The process comprises flowing water through a first chambercontaining a first media supporting aerobic bacteria and then flowingthe water through a second chamber containing a second media comprisingsulfur that supports an anaerobic bacteria that will reduce nitrates tonitrogen gas through a biological process. Preferably, the aerobicbacteria are capable of reacting with ammonia and nitrites in the water,to generate nitrates, while also generating carbon dioxide andsignificantly decreasing the level of oxygen in the water to a minimumlevel. Preferably, the anaerobic bacteria are capable of being supportedby the sulfur substrate even at times when the water being treatedcontains little or no nitrates. One such type of bacteria is Thiobacilusdenitrificans, although other bacteria may be used as discussed below.The denitration process achieved by these bacteria reduces nitrateconcentrations in the water, while at the same time decreasing the pH ofthe water. Preferably, the water is then flowed through at least onechamber to increase the pH of the water. By means of example only, thechamber might contain a calcium source. As water flows through a calciumchamber, the calcium source reacts with hydrogen ions in the water toincrease the pH of the water. Preferably, the water flows from thesulfur chamber through multiple chambers having different watertreatment characteristics. In one embodiment, several chambers havedifferent calcium sources.

In salt water applications, especially ones having live coral, the useof multiple chambers with different calcium sources is highly preferred.These chambers in the preferred embodiment include dolomite, thenaragonite, and then calcite, or other forms of calcium that respectivelyhave the qualities and characteristics of these preferred forms ofcalcium. The water may then be flowed through one or more additionalchambers or devices for degassing the water, removing additionalcontaminants, as well as adding oxygen to the water, before the water isreturned to the aquarium.

Another embodiment of the invention is directed to a biological systemfor conditioning water in an enclosed environment for aquatic life. Thesystem comprises a first chamber containing a first media capable ofsupporting aerobic bacteria. A second chamber is connected to the firstchamber by a first pathway through which the aquarium water flows. Thesecond chamber contains a second media, preferably sulfur, that iscapable of supporting anaerobic bacteria, such as Thiobacilusdenitrificans bacteria. A third chamber, which contains a first calciumsource, may be connected to the second chamber by a second pathwaythrough which the aquarium water flows. Additionally, a fourth chamber,containing a second calcium source, may be connected to the thirdchamber by a third pathway through which the aquarium water flows. In apreferred embodiment, a fifth chamber may be added for containing athird source of calcium. Preferably, the system includes one or moreadditional chambers or devices for degassing the water before the wateris returned to the aquarium.

As explained below, the methods and apparati of the present inventionmay be used alone, or in connection with other filtration systems, andmay be applied to large and small aquariums, to provide clean andhealthy water to aquatic life, in an efficient and economic way thatdoes not harm the environment. The disclosed methods and apparati canalso be used, in whole or in part, in other applications where toxicnitrates must be removed from water and the water must be efficientlyand economically treated. For example, the denitration and treatmentprocesses of the present invention can be applied to aquatic farms,livestock farms, sewage treatment, the purification of drinking water,industrial waste water treatment, and similar applications wherenitrates are generated in the water supply and must be controlled, alongwith other aspects of the water.

These and other embodiments of the invention will be discussed morefully in the detailed description of the embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention and, together with the written description, serve to explainthe principles of the invention.

In the drawings:

FIG. 1 is a process flow diagram representing the flow of the variousprocess steps which may be used for conditioning water, according to thepresent invention.

FIG. 2 is a diagrammatic representation of one system for conditioningwater for aquatic life, according to the present invention.

FIG. 3 is a diagrammatic representation of a chamber containing floatingmedia capable of supporting aerobic bacteria, according to an embodimentof the present invention.

FIG. 4 is a diagrammatic representation of a denitration chambercontaining sulfur media capable of supporting anaerobic bacteria,according to an embodiment of the present invention.

FIGS. 5 and 6 are diagrammatic representations of chambers of thebiological system which contain arrangements of media comprisingcalcium, according to certain embodiments of the present invention.

FIG. 7 is a diagrammatic representation illustrating certain dimensionsof one chamber of the biological system, according to an embodiment ofthe present invention.

FIGS. 8 a to 8 c are diagrammatic representations of top and side viewsof arrangements of the various chambers of the biological system,according to an embodiment of the present invention.

FIG. 9 is a diagrammatic representation of denitration chamberscontaining sulfur media capable of supporting anaerobic bacteria,according to an embodiment of the present invention.

FIG. 10 is a diagrammatic representation of sulfur containing mediacapable of supporting anaerobic bacteria, according to an embodiment ofthe present invention.

FIG. 11 is a diagrammatic representation of denitration chamberscontaining sulfur media capable of supporting anaerobic bacteria,according to an embodiment of the present invention.

FIG. 12 a is a diagrammatic representation of a further embodiment ofthe biological system having a chamber containing sulfur and a chambercontaining calcium, according to the present invention.

FIG. 12 b is a diagrammatic representation of a further embodiment ofthe biological system similar to the embodiment of FIG. 12 a, but havingan additional chamber containing a media for aerobic bacteria.

FIG. 13 is an additional diagrammatic representation of the biologicalsystem of FIG. 12, which shows an outside view of the system, includingdetails of the air pumping system in relation to the inlet and outletspipes.

FIG. 14 is a three dimensional view of the biological system of FIG. 8,according to the present invention.

FIG. 15 is a three dimensional view of a biological system comprisingmultiple sections arranged in a single cylindrical chamber, according toanother embodiment of the present invention.

FIG. 16 is a diagrammatic representation of an activated carbon chamber,according to an embodiment of the present invention.

FIG. 17 is a diagrammatic representation of a system for conditioningwater for large aquariums, according to an embodiment of the presentinvention.

FIGS. 18 a and 18 b are diagrammatic representations of side and topviews, respectively, of a chamber which utilizes algae to removecontaminants from water, according to an embodiment of the presentinvention.

FIG. 19 a is a diagrammatic representation illustrating the placement ofa light source within a chamber which utilizes algae to removecontaminants from water, according to a further embodiment of thepresent invention.

FIG. 19 b is a diagrammatic representation of a light source which maybe used in the chambers illustrated in FIGS. 18 and 19 a, according toan embodiment of the present invention.

FIGS. 20 a to 20 c are diagrammatic representations illustrating variousprotein skimmer embodiments, according to the present invention.

FIGS. 21 a to 21 c are diagrammatic representations illustrating aneductor for mixing fluids, according to an embodiment of the presentinvention.

FIGS. 22 a and 22 b are diagrammatic representations illustratinganother embodiment of an eductor for mixing fluids, according to thepresent invention.

FIGS. 23 a to 23 f are diagrammatic representations illustrating achamber for removing sulfates, according to an embodiment of the presentinvention.

FIG. 24 illustrates an aerobic chamber, according to an embodiment ofthe present invention.

FIG. 25 illustrates a calcium chamber, according to an embodiment of thepresent invention.

FIG. 26 illustrates a system for filtering water in aquariums or aquaculture applications, according to an embodiment of the presentinvention.

FIG. 27 illustrates a bio-filter chamber, according to an embodiment ofthe present invention.

FIGS. 28 a and 28 b illustrate a support for a mixing eductor used inthe bio-filter chamber of FIG. 27, according to an embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, reference is made to the accompanyingdrawings, in which is shown by way of illustration specific exemplaryembodiments in which the invention may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the invention, and it is to be understood that otherembodiments may be utilized and that changes may be made withoutdeparting from the scope of the present invention. The followingdescription is, therefore, not to be taken in a limited sense. Whereverpossible, the same reference numbers are used throughout the drawings torefer to the same or like parts.

The methods and systems of the present invention can be applied todifferent types of aquarium and similar environments for aquatic life,in both fresh water and salt water applications. The systems and methodsof the present invention can be designed to control the quality of watersupporting fish, as well as coral and other aquatic life, in a varietyof different aquariums and similar environments, ranging from relativelysmall household aquariums to aquariums of millions of gallons, or more.While the broadest principles of the invention are applicable to many,if not all, of these potential applications, preferred methods andsystems are disclosed for specific applications, or ranges ofapplications.

The physical characteristics of the systems of the present invention canvary considerably, while still practicing the present invention.Examples of some, but by no means all, of the potential embodiments ofthe present invention are shown in FIGS. 2 through 28 b.

FIG. 1 is a process flow diagram illustrating various process steps 1 to8 of the present invention, which will now be used to describe theprocess of the present invention in general terms. All of the processsteps shown in FIG. 1 are not required for every embodiment of theinvention. Rather, the process steps utilized may be chosen as desiredto meet the requirements of the aquarium, or other aquatic system, forwhich the process is employed. Examples of preferred embodiments of theinvention will also be provided.

Referring to FIG. 1, the process of the invention may comprise afiltration step 1, in which the water to be treated passes through afilter, followed by an aerobic bacteria processing step 2, and ananaerobic bacteria processing step 3. Additional process steps mayinclude steps for adding desirable nutrients to the water, adjusting pH,reducing undesirable gases, adding oxygen to the water, or any otherstep which is desirable for further conditioning of the water. Forexample, in steps 4 and 5, the water being processed is flowed over twoseparate chambers to add calcium and increase pH. In one embodiment, thewater flows over two separate calcium mixtures. Step 6 represents adegassing process wherein the water is flowed through a degassingchamber which, among other things, removes undesirable gases andcompounds from the water. Alternatively, or in addition to degassingstep 6, a process step 7 may be used for reducing hydrogen sulfide gasfrom aquarium water by flowing the water through an activated carbonchamber. Still another alternative process is represented by step 8, inwhich water is flowed through a chamber, termed “the oxytower,” whichcontains algae and/or bacteria in order to remove certain undesirablecontaminants, increase pH and add oxygen to the water. Each of thesesteps is not necessary for each potential application to a particularaquarium or problem.

The process steps shown in FIG. 1 may each be performed in separatechambers. Alternatively, two or more of the process steps may beperformed in a single chamber or a chamber or housing having multiplesections devoted to each of the process steps performed therein.Examples of systems for carrying out the processes of the presentinvention will be provided in the form of preferred embodimentsdiscussed herein.

The process steps of FIG. 1 are associated with each other so that waterto be treated flows from the aquarium 10, or other closed environment,through one chamber to another and then returns to the aquarium. Thesystem in which the process steps of FIG. 1 occur will at times bereferred to herein as the Nitrafix system.

The water to be treated may flow directly from the aquarium to theNitrafix system, and then return to the aquarium. Alternatively, theaquatic system may include a sump 9, as shown in FIG. 1. Such sumps areknown in the aquarium art for collecting, filtering and otherwisetreating aquarium water outside of the aquarium tank. Water flows fromthe aquarium tank to the sump and then returns to the aquarium tank. Allor a portion of the water flowing from the sump may be diverted to theNitrafix system for processing before the water is returned to theaquarium tank. After processing by the Nitrafix system, the water may bereturned either to the sump, as shown in FIG. 1, or directly to theaquarium tank.

Generally, the flow rate through the sump is approximately three timesthe volume of the aquarium per hour, as is conventionally known. Theamount of water flowed through the denitration system of the presentinvention is significantly less. For example, it has been found that thewater applied to the denitration chamber according to the presentinvention, on the other hand, can be about 1% of the volume of theaquarium, per hour and perform well. The particular flow rate for aspecific application can be varied and optimized, through routinetesting. A flow rate ranging from about 1% to about 10% of the volume ofthe aquarium per hour is believed to be optimum for most applications,although about 1% to about 3% may be more preferable for aquariumapplications.

The means for forcing the water through the Nitrafix system may be anymeans known in the art, such as use of an air pump, air stone ormechanical pumping device. A gravity feed, such as where the water issiphoned from the aquarium tank to the Nitrafix system may also be used,as is known in the art.

A more in-depth discussion of each of the process steps of FIG. 1 willnow be provided. Step 1 of the process is an optional filtering step bywhich particulates or other solid matter is removed from the water to betreated. The water to be treated may contain various types of solidmater, such as fish waste, sand, and algae. Removing this solid matterfrom the water not only provides for a cleaner, more attractiveaquarium, but also helps to prevent clogging of the Nitrafix system.This filtration may be accomplished by using a mechanical filter, suchas a screen, or cartridge filter. Other filters known in the art mayalso be used. In order to prevent clogging of the Nitrafix, it ispreferred that the filter remove particulates which are 50 microns orlarger.

Step 2 of the process, shown in FIG. 1, uses aerobic bacteria processingto treat the water. The water to be treated is flowed through a chamberwhich contains a support media that preferably has a large surface areaon which the aerobic bacteria may colonize. Examples of such mediainclude sand, plastic particles, and similar media. The aerobic bacteriaexist and thrive in the aquarium water and will colonize on the mediawithin the chamber as the system is operated. The type of aerobicbacteria utilized in step 2 may include, for example, nitrosomonas andnitrobacter bacteria. These naturally occurring bacteria break downammonia and nitrites in the aquarium water and form nitrates. In theprocess of breaking down the ammonia and nitrites, the aerobic bacteriaproduce CO₂ and reduce the levels of dissolved oxygen in the water.Preferably, the chamber housing the aerobic bacteria, as well as themedia in the chamber, are sized so that most, if not all, oxygen in thewater is removed, as the water flows through the chamber. While thischamber preferably breaks down ammonia and nitrites, the chamber couldalso be designed to use other chemical or mechanical agents that takeall or most of the oxygen out of the water, before it flows through thenext chamber, and still be effective in reducing nitrates from thewater.

The total average dissolved oxygen content in water in aquariums withnormal loading and feeding is approximately 5 ppm. Of course, theaverage level of dissolved oxygen for each aquarium may be greater orless than 5 ppm, depending on the fish load and feed supply to theaquarium. It is preferable that the process of step 2 substantiallyreduce the dissolved oxygen content of the water leaving the aerobicbacteria processing chamber, as compared with the level of dissolvedoxygen in the water entering the chamber, in an amount sufficient tosignificantly increase the nitrate reduction in chamber 2 over what itwould have been if the step 2 process had not been employed. Thus, it ispreferable that the total dissolved oxygen content be reduced to, forexample, less than 5 ppm, and more preferably, to less than 2 ppm, andstill more preferably to about 1.64 ppm or less.

Following the aerobic process of step 2, an anaerobic processing step 3is next employed to autotrophically reduce the concentrations ofnitrates in the water by a process known as sulfur denitration. In thepreferred embodiment, sulfur denitration utilizes sulfur oxidizingbacteria such as Thiobacillus denitrificans. Under aerobic conditions,these bacteria will use oxygen to oxidize sulfur. However, wheninsufficient oxygen is present, the bacteria use nitrate to oxidizesulfur to sulfate. Thus, the reduction of oxygen in step 2 permitsnitrates existing in the water to be efficiently utilized by thebacteria in an anaerobic type process. In this manner, the concentrationof nitrates in the water is reduced in the step 3 process.

In addition to reducing nitrates, the bacteria in the denitrationchamber may also reduce other undesirable nitrogen compounds, such asnitrites. The denitration process also decreases the pH of the water. Itshould also be noted that for the first few days of operation fromstartup, the denitration chamber may produce nitrite. However, theamount of nitrite produced will thereafter decrease and the chamber willpreferably begin to help reduce nitrite levels.

The aerobic process of step 2 helps to insure that the oxygenconcentration is sufficiently decreased, while the nitrate concentrationis sufficiently increased, in order to maintain an efficient anaerobicsulfur denitration process. Consequently, less support media for theanaerobic bacteria is needed to remove the desired amount of nitratesthan if the aerobic process was not used. This allows for a smaller, andsignificantly lighter weight, denitration chamber for the step 3process, since the sulfur media used in the chamber can be relativelyheavy. Additionally, the reduction in the level of dissolved oxygen inthe chamber may help to prevent the proliferation of certain undesirablesulfate reducing bacteria, such as Beggiatoa Alba. Beggiatoa Alba areknown to be filamentous, creating a thick, slimy coating on the sulfurmedia, which could cause the chamber containing the sulfur media toclog.

The aerobic bacteria process of step 2 should preferably occur inlinewith, and in close proximity to, the denitration step 3, so as toprevent reoxygenation of the water before it enters the denitrationchamber.

The applicant believes that it is also possible that carbon dioxideproduced by the aerobic bacteria in step 2 allows the bacteria in thedenitration chamber to remove nitrates more efficiently. However, it isnot intended that the above described mechanisms of the bacteriaprocesses limit the full scope of the invention as defined by theclaims.

The denitration step 3 utilizes a media that supports the anaerobicbacteria that break down nitrates in the water. Preferably the mediawill support the anaerobic bacteria even when there are lowconcentrations of nitrates in the water. In a preferred embodiment, themedia is sulfur and the bacteria is Thiobacilus denitrificans. Asdiscussed above, under the proper conditions where oxygen levels are lowenough, these bacteria carry out anaerobic respiration, reducingnitrates while oxidizing elemental and/or reduced sulfur to sulfate. Forexample, the dissolved oxygen content of the water entering thedenitration chamber is preferably between 0 to 2 ppm. Other conditions,such as the temperature and the pH of the water should also bemaintained at healthy levels for the bacteria. For example, ifThiobacillus denitrificans are employed, the water in the chamber shouldpreferably have a temperature ranging from 25 to 30 degrees Celsius anda pH ranging from about 6 to about 8, although the bacteria may functionoutside of these ranges. Other bacteria which reduce nitrate whileoxidizing sulfur may also be used in place of or in addition toThiobacilus denitrificans. Examples of such bacteria which may beacceptable for use in the present invention include Thiobacillusversutus, Thiobacillus thyasiris, Thiosphaera pantotropha, Paracoccusdenitrificans, and Thiomicrospira denitrificans. The scope of theinvention includes the application of any anaerobic bacteria that cansurvive in a media within a chamber and efficiently and effectivelyperform the denitration process of the present invention on a flow ofwater having nitrates that must be removed.

The structure enclosing or creating the denitration chamber ispreferably opaque so that little or no light is in the chamber. This isbecause the anaerobic bacteria do not like light. If placed in a lightedenvironment, the bacteria will move toward the center of the chamberwhere the environment is darker. This would thereby decrease theefficiency of the bacteria in eliminating or reducing nitrates from thewater.

The level of nitrate in the water at the outlet of the denitrationchamber may depend on the amount of nitrate in the inlet flow to thedenitration, the flow rate of water through the denitration chamber, andcontact time of the water with the sulfur media. Under optimumconditions, the denitration chamber may reduce substantially all of thenitrates. For example, Nitrate levels at the outlet may range from about0 ppm to about 20 ppm, and more preferably from about 0 ppm to about 10ppm, and still more preferably from about 0 to 5 ppm.

The pH of the water will be reduced during the denitration process.Consequently, the pH of the aquarium water leaving the denitrationchamber 120 may range from about 4 to about 8, and more preferably fromabout 5 to about 7. Such lower ranges may not be healthy for some typesof fish. The pH of the water leaving the denitration chamber may beadjusted by, for example, adjusting the flow rate of the water throughthe chamber. Another way to adjust the pH to desirable levels is to addcalcium to the water. The calcium is beneficial to many sea organisms,such as corals, that use the calcium to form their skeletons and/orshells. Furthermore, the bacteria used in the aerobic and anaerobicprocesses of the Nitrafix are more effective if the pH is kept within ahealthy range for the particular bacteria being used, such as, forexample, a pH of 6 to 9. Therefore, in closed systems, where the wateris continually recirculated through the Nitrafix system, using calciumto maintain the proper pH can help to make the process more effective.

In order to adjust the pH of the water to the desired range, as well asto add calcium to the water, the process of FIG. 1 includes steps 4 and5, in which the water leaving the denitration chamber is flowed overmultiple calcium sources. Different calcium sources, which havedifferent solubilities, are preferably used to control not only theamount and type of calcium which is dissolved in the water, but also toincrease the life of the calcium media in the system before new calciummedia must be added. Acceptable sources of calcium include dolomite,aragonite, calcite, crushed coral, as well as other known sources. Thesesources of calcium include other minerals and trace elements, such asmagnesium and strontium, which can also be beneficial to aquatic life.As the water flows through the calcium sources, the calcium sourcesdissolve to add beneficial amounts of the calcium and other elements tothe water, in addition to increasing the pH of the water. While FIG. 1shows the calcium being added in two steps, the calcium may be added ina single step, or in three or more steps.

Adding the calcium in multiple steps has the benefit of allowing thecalcium source to be arranged to give long life with a minimum amount ofclogging. For example, the calcium source may be arranged so that thewater coming from the denitration chamber contacts the least solublecalcium sources before the other more soluble calcium sources. This willresult in increased life of the calcium media in the system because theacidity of the water is reduced when it contacts the less solublecalcium sources, so that the water having a reduced acid content willdissolve the more soluble calcium media at a slower rate. Furthermore,very fine media, such as calcite sand, can create clogging problemswithin the calcium chambers. Clogging may be prevented by utilizing alarge media, such as crushed coral, in the same chamber as the calcitesand. Specific examples of how the calcium should be arranged to providefor long life and reduced clogging will be provided in the preferredembodiments.

In certain applications, no calcium may be added by omitting steps 4 and5 altogether. In such applications, the pH of the water is preferablyraised by other means before it is resupplied to the aquarium.

A degassing step 6 may also be added to the process. The degassing stepmay be performed in a degassing chamber in which the water is degassedand re-oxygenated before returning to the aquarium tank. The degassingstep provides the advantages of reducing odorous gases, such as hydrogensulfide gas, and other undesirable contaminants, which may be emittedfrom the biological processes occurring within the chambers. Degassingcan also be useful for raising the pH of the water by reducing carbondioxide levels.

For example, in one embodiment a conventional protein skimming step maybe added to the process of FIG. 1, which removes undesirable compounds,such as nitrogenous and other organic compounds, raises the pH, and addsoxygen to the water. Other systems for degassing, which are known in theart, may also be used for step 6, including a dripping system, such as adegassing tower, compressed air through stone, and the Venturi system.

Another optional process step utilizes an activated carbon chamber, asillustrated in FIG. 16. The chamber 16 may be added to the system forreducing levels of hydrogen sulfide gas. When the Nitrafix system isrunning at the desired flow rate, it produces relatively little, if any,hydrogen sulfide. However, when the flow through the Nitrafix system isstopped for a period of time, or if the flow is too low to providesufficient nitrate to the bacteria in the denitration chamber, certaintypes of sulfur reducing bacteria will begin to reduce sulfate tohydrogen sulfide. If large enough amounts of hydrogen sulfide gases areproduced, this can be lethal to aquatic life, such as fish. In order toreduce the amount of hydrogen sulfide generated by the Nitrafix systemduring these down times to acceptable levels, an activated carbonchamber 20, as illustrated in FIG. 16, may be employed. Such a chambermay also reduce other gases that are generated through the process ofthe present invention.

In one preferred embodiment, chamber 20 is filled with activated carbon21. The chamber 20 comprises an inlet 22 for allowing water to flow intothe chamber, which is located a distance “A” from the top of thechamber, and an outlet 23 located near the bottom of the chamber. Waterentering chamber 20 flows down through wet zone “B” of the activatedcarbon chamber, which acts to degas and adsorb contaminants, includinghydrogen sulfide gas in the water. Gas emissions, including hydrogensulfide gas, flow up through dry zone “A” of the activated carbonchamber and out through vents 28. The hydrogen sulfide gas is adsorbedby the activated carbon in the dry zone, thus reducing the “rotten egg”smell which is characteristic of hydrogen sulfide gas. Screens 26located at the mouths of inlet 22 and outlet 23 help prevent the chamberfrom becoming clogged.

Preferably, chamber 20 is employed in the process after the denitrationstep and before the water is returned to the aquarium tank. For example,chamber 20 may be employed directly at the outlet of the denitrationchamber, or after the calcium chamber or chambers of the Nitrafixsystem. Alternatively, chamber 20 may sit in the sump. For example, thechamber may be fastened to the edge of the sump by attachment 27. Asshown in FIG. 16, the outlet 23 may be placed on the bottom surface 29of chamber 20, rather than on the side surface, as indicated by thedotted lines. Preferably, chamber 20 should be placed at an elevationwhich is above the water level in the sump so that the water fromchamber 20 may run down into the sump.

Activated carbon, or any other media known in the art which would allowremoval of the hydrogen sulfide gas, could be used in chamber 20.Examples of preferred types of activated carbon for use in the presentinvention are those made from wood or coconut shells. In one embodimentthe activated carbon is Granula Activated Carbon (GAC). The activatedcarbon granules are preferably small in order to provide a high surface.For example, the activated carbon may have an average granule size offrom ¼ to ⅛ inches or smaller.

Alternatively, the activated carbon system may include multiplechambers. For example, a first wet carbon chamber through which thewater being treated flows may be utilized for removing contaminants,such as hydrogen sulfide gas, from the water. A second dry carbonchamber located above the water level could be used to removeundesirable gaseous emissions. Media other than activated carbon may beused in these systems, as long as the media provides the desiredadsorption of the contaminants to be removed.

Yet another novel processing step 8, which may be added to the Nitrafixprocess, involves the use of algae and bacteria to break down and/orremove unwanted contaminants in the water. This process, which isperformed in a chamber called “the oxytower,” will add oxygen, raise thepH, remove phosphates, sulfates and remaining nitrates from the water. Adetailed discussion of the oxytower is provided below in the descriptionof the preferred embodiments.

Still another processing step, not shown in FIG. 1, may be added to theprocess of FIG. 1 for reducing sulfate and/or hydrogen sulfideconcentrations in aquarium water.

This process step utilizes a desulfator, which will be described belowin the description of the preferred embodiments. The process forreducting sulfates may potentially be carried out anywhere in theprocess. For example, the process may be carried out directly after thedenitration step 3, or after the calcium step 5.

While FIG. 1 indicates that any one of process steps 6, 7 and 8 may beused to treat the water, in other embodiments a combination of thesesteps may be added to the process in order to achieve the desired waterquality. For example, both an activated carbon chamber and a proteinskimmer may be used. In addition, in some applications the water leavingthe denitration chamber 2 can flow directly to an oxytower or degassingtower and then to the aquarium.

The materials for constructing the systems of the present inventiondescribed in this application, including the chambers and connectingpipes for these systems, are preferably chosen to be safe and non-toxicto aquatic life and are corrosion resistant. Examples of such materialsinclude plastics, such as PVC, polyethylene, polypropylene, methacrylicor acrylic plastic, or fiber glass reinforced plastic (FRP), or metals,such as stainless steel.

PREFERRED EMBODIMENTS

Certain preferred embodiments will now be described. These embodimentsare not to be taken in a limiting sense, but as illustrations of thevarious concepts of the present invention.

FIG. 2 provides a diagrammatic representation of one embodiment of theNitrafix system for conditioning aquarium water, according to thepresent invention. The Nitrafix system 100, as illustrated in FIG. 2,comprises an aerobic bacteria chamber 110, a denitration chamber 120,containing anaerobic bacteria, and two chambers, 130 and 140, whichcontain calcium sources. The system may also comprise an additionalchamber 150, which is used as a degassing chamber.

A detailed description of chambers 110, 120, 130, and 140 of system 100will now be provided with respect to FIGS. 3, 4, 5, and 6, respectively.As shown in FIGS. 3, 4, 5 and 6, each of the chambers is divided intothree separate sections by perforated plates 102 and 103. The topsection 109 of each chamber may be filled with activated carbon, whichis useful for absorbing or removing odorous gases which may be emittedfrom the biological processes occurring within the chambers, such as thehydrogen sulfide gas emitted from the denitration chamber 120. Section108 of each chamber is where the active processes of the system 100occur within each chamber. For example, section 108 is filled with amedia which supports the aerobic and anaerobic bacteria of chambers 110and 120, respectively, and the calcium sources of chambers 130 and 140.The bottom section 107 of each of the chambers is an empty zone, whichallows for improved circulation and dispersion of the water through themedia in section 108.

FIG. 3 illustrates one example of the aerobic bacteria chamber 110 ofsystem 100. Section 108 of chamber 110 may be partially or completelyfilled with a support media 112, which acts as a substrate for theaerobic bacteria. The aerobic bacteria already exist in the water of theaquarium and will readily colonize on the substrate. The media 112 maybe any type of media that can support colonization of aerobic bacteria.While a media having any practical size and shape may be used, mediahaving a high surface area is preferred. For example, sand and othermedia having relatively high surface areas may be used. One preferredform of support media is plastic, which may be in the form of smallspheres or tubes, although any shape known in the art may be used. Theplastic media is lightweight and may float in the aquarium water. Itdoes not clog easily, and provides a large surface area for bacterialcolonization. One example of such a plastic media is known as biofilm.Examples of biofilm which may be used include Kaldnes or Bee-Cell, bothof which are manufactured by Water Management Technologies, Inc. Othermedia like Bio-Chem stars from RENA may also be used.

FIG. 4 illustrates one example of denitration chamber 120, according toan embodiment of the invention. Section 108 of the denitration chamber120 may be filled partially or completely with a media 122 comprisingsulfur, which supports the bacteria used in the anaerobic process.Preferably most or all of the chamber is filled with sulfur, so that thechamber will have a long life. Preferably, the sulfur should have a sizeand shape which maximize surface area, so that more anaerobic bacteriacan live in a given space. In one preferred embodiment, the media maycomprise 90% or more sulfur by weight, and more preferably 99% to 100%sulfur by weight. Thus sulfur preferably has a granular or pastilleshape with a diameter of 3 to 5 mm, although any size and shape known inthe art may be used. This media preferably has a relatively long life inorder to avoid having to frequently replace the media. For example, somemedia known in the art may have a life time of up to 20 years or more.

The chamber, and thus the amount of sulfur and anaerobic bacteria thatcan be held by the chamber, preferably is sized and shaped to containsufficient anaerobic bacteria to reduce the nitrates in the water tosafe levels, over an extended period of time, preferably for at least 1to 10 years. The walls of the chamber are preferably opaque. The degreeof reduction of nitrates in the water depends on a number of variables,including the flow rate of water through the chamber, the surface areaof the supported media, the level of nitrates in the water beforeprocessing with the Nitrafix, and the total volume of water to betreated.

Referring to FIGS. 5 and 6, section 108 of calcium reaction chambers 130and 140 may be filled partially or completely with a media comprisingcalcium. Preferably, multiple sources of calcium may be used. Asdiscussed above, examples of calcium media which may be used includecrushed coral, carbonate minerals such as dolomite (CaMg(CO₃)₂), andforms of CaCO₃, such as aragonite and calcite. For example, the mediamay be in a gravel form having an average diameter of 3 to 5 mm.

As shown in FIG. 5, the portion of section 108 which is nearest to theinlet 131 preferably is filled with dolomite 132, while the portionnearest to the outlet 134 is filled with aragonite media 133. Water fromthe denitration chamber first flows through the dolomite media, whichhas a rate of solubilization that is slower than that of aragonite. Asthe water flows over the dolomite, the pH of the water is raised (i.e.,the acidity of the water is decreased). The water having decreasedacidity then flows through the faster solubilizing aragonite media,which results in the aragonite media being dissolved more slowly than ifit had been dissolved in the more acidic water entering chamber 130. Inthis manner the longevity of the media in the calcium chamber isincreased and a desirable mineral content for the water is achieved.

FIG. 6 illustrates one example of an arrangement of calcium media whichmay be used in reaction chamber 140. Section 108 of chamber 140 isfilled with calcite 142, which is surrounded by crushed coral 143. Inone embodiment, the calcite media may be in the form of sand, which iscontained in a water permeable bag. This arrangement has the benefit ofpreventing clogs in the chamber, since the water can easily circulatethrough the crushed coral surrounding the calcite. The calcite isbeneficial for aquariums containing coral, algae, and invertebrate,which use calcite to make their skeletons and/or shells. In analternative embodiment (not shown) for chamber 140, a calcium mediafills the lower portion of section 108, while activated carbon is placedin the top portion of section 108. The activated carbon in section 109remains dry, while water flows through the activated carbon in section108. In this embodiment, hydrogen sulfide gas is removed from the waterby the activated carbon in section 108, while the activated carbon insection 109 reduces hydrogen sulfide gas emissions, similarly asdescribed above with respect to the activated carbon chamber of FIG. 16.The volume of activated carbon in section 108 may be approximately equalto the volume of dry activated carbon in section 109, although theamounts in either section may be optimized to provide the desiredcontact time between the activated carbon and either the water insection 108 or the emissions in section 109, in order to obtain thedesired benefits of the activated carbon.

In general applications, sulfur used in the denitration chambers mayhave a useful life within the range of 20 years, while the calcium whenplaced in the preferred embodiment may have a life of about 1 to 5years. In general, media having longer life times is preferable in orderto increase the time period between media replacements. In largerapplications, at least certain components and materials, such as sulfur,calcium, and other media, etc. need to be periodically replaced orcleaned.

As discussed above, a degassing chamber 150 may be added to thebiological system 100, as illustrated in FIG. 2. While the degassingchamber 150 may be used for smaller aquariums, it is more often used forlarger aquariums. Any conventional degassing systems, such as thosediscussed above, may be used as the degassing chamber 150. Additionally,the activated carbon chamber of FIG. 16 or the oxytower of FIG. 18, mayalso be used in place of degassing chamber 150.

Water may be forced through the chambers using any workable arrangement.In one embodiment, as can be seen from the flow arrangements of FIG. 2,water flow through aerobic chamber 110 is from top to bottom, while thedirection of flow in chambers 120, 130 and 140 is from bottom to top. Aflow rate from the bottom to the top in all, or at least chambers 120,130, and 140, is preferred because such a flow helps prevent clogs inthese chambers and allow gases formed in the chambers to better escapethrough the tops of the chambers. The chamber covers preferably areperforated so as to allow the gases to escape. Regarding degassingchamber 150, the flow through the chamber may be from top to bottom, asshown in FIG. 2.

The chambers of the biological system 100 may have any workable shape,such as a cylindrical or box shape. The size of the chambers may alsovary according to the requirements of the aquarium.

Another preferred embodiment of the present invention is illustrated inFIGS. 8 a to 8 c. A three dimensional view of this system is shown inFIG. 14. This embodiment is similar to that of system 100, illustratedin FIG. 2, except that it has been modified so that all of the chambersare contained within a single integral unit to provide for a compactsystem design. Further, in the illustrated embodiment, all of thechambers have the same shape and size, but respective chambers can besized differently, as circumstances require. All of the chambers of theFIG. 8 embodiment may fit into a single cubic shaped container, asillustrated in FIG. 14.

FIG. 8 a illustrates a top view of an embodiment of a system whereinaerobic chamber 110, denitration chamber 120, and calcium chambers 130and 140 are each arranged within a single container. As shown in FIG. 8b, water flows into the system through inlet 101, which comprises a gatevalve 101 a, which allows for control of the flow rate of water throughthe system. Other types of valves, such as a needle valve, may also beused. Inlet 101 also includes a clear section of conduit 101 b, whichallows visual inspection of the water flow in order that clogging may bedetected. Both inlet 101 and outlet 141 may comprise, for example, PVCpipe which is ½ inch in diameter.

The water flowing into the system flows down through aerobic chamber 110and enters near the bottom of chamber 120 through an opening in section109. The water then flows up through the sulfur media in section 108 ofdenitration chamber 120. The water exits chamber 120 near the top ofsection 108 and flows straight across into the top of section 108 ofchamber 130 through openings 121 in the chamber wall, so that the waterflows from top to bottom in calcium chamber 130. This flow arrangementallows for a more compact design than the flow arrangement illustratedin FIG. 2, in which the water in chamber 130 flows from bottom to top.

The water flowing from calcium chamber 130 enters the second calciumchamber 140 near the bottom of section 109, flows up through the mediaof section 108, and exits the system through outlet 141. Outlet 141 alsocomprises an overflow elbow 141 b with a clear section of conduit 141 a,which allows for visual inspection to determine if the system isoverflowing. Multiple openings, as illustrated by openings 121 in FIGS.8 b and 8 c, may also be used to allow water to flow between chambers110 and 120 and chambers 130 and 140. Vents 150 may be placed in thecoverings 104 of the chambers to allow gases produced in the chambers toescape from the system. Vents 151 may also be placed between adjacentchambers which allows gas flow between the upper sections 107 of eachchamber containing activated carbon.

A section of tubing may be used to connect a vent (not shown) with oneof the vents 150 in order to equalize the pressure between the inlet andthe Nitrafix chambers. This helps to ensure that the level of water inthe clear plastic tube 101 b accurately reflects the level of water inthe Nitrafix. When water is flowing through the Nitrafix systemproperly, the level of water in the clear tube 101 b should be at aboutthe same level as the outlet 141. If the level of water in tube 101 b islower than the outlet 141, an air bubble may be formed in the outlettube, or the system may be clogged. If the water is flowing through theclear elbow 141 a above the outlet on the outlet side, then the systemis overflowing.

As discussed above, section 108 of each of the chambers 110, 120, 130and 140 of the embodiment of FIG. 8 may respectively contain the samemedia as described above for chambers 110, 120, 130 and 140 of theembodiment illustrated in FIGS. 2 to 6. However, in another preferredembodiment, the upper portion of section 108 of chamber 140 of the FIG.8 embodiment may be filled with activated carbon, while the lowerportion of section 108 may be filled with calcium, such as the crushedcoral and calcite sand arrangement illustrated in FIG. 6 a. The volumeof activated carbon in section 108 may be approximately equal to thevolume of dry activated carbon in section 109, although the amounts ineither section may be optimized to provide the desired contact timebetween the activated carbon and either the water in section 108 or theemissions in section 109, in order to obtain the desired benefits of theactivated carbon. In this manner, the benefits of running the waterthrough the activated carbon, such as degassing, may be realized, whilestill allowing the system of FIG. 8 to remain compact. Sections 107 ofthe chambers in the FIG. 8 embodiment may also contain dry activatedcarbon and sections 109 may remain empty, as described above for theembodiment illustrated in FIGS. 2 to 6.

The container for the Nitrafix of FIG. 8 may be made of any appropriatematerial known in the art. In one embodiment, the material is ¼ inchplastic. Other materials, such as PVC, polyethylene, polypropylene,methacrylic or acrylic plastic, or fiber glass reinforced plastic (FRP),or stainless steel. Since the anaerobic bacteria are more efficient atremoving nitrates in a dark environment, the container preferably isopaque, so as not to let light through. For example, the container maybe a black acrylic plastic.

The size of the FIG. 8 embodiment may be adjusted as appropriate fortreating any size aquarium. For example, aquariums of up to 5000 gallonsor more may be treated. For example, an embodiment of FIG. 8, known asthe N-500, having a width of 14 inches, a depth of 14 inches, and aheight of 20 inches, may be used to treat aquariums holdingapproximately 10 to 500 gallons.

The ratio of chamber height to chamber volume may be adjusted in orderto control the amount of time the water maintains contact with a givenvolume of media within each chamber, as well as the volume (and thus thesurface area) of media within the chamber. A longer contact time and/ora greater surface area of the media within the chamber can allow formore efficient processing for any given volume of media and/or a fasterprocessing time for a given flow rate of water through the chamber.Referring now to FIG. 7, the height H2 of section 108 of the chamber maybe chosen to be 3 to 5 times L, where L is the diameter of the chamberfor a cylindrical chamber, or the width of the chamber for a cubic orbox shaped chamber. The heights, H1 and H3 of sections 109 and 107,respectively, can be any height. In one embodiment, H1 and H3 are eachchosen to have a height of at least ⅛ the height of H2.

The specifications for the systems of the present invention, such as thedimensions of the chambers, the volume of media to be used, and the flowrate through the system, will depend on certain parameters. Theseparameters may include, for example, the starting pH and nitrate levelof the aquarium to be treated, the fish load and amount of feed added tothe aquarium, as well as the desired pH and nitrate levels for theaquarium. Given the necessary parameters, the optimum specifications foreach of the systems of the present invention, as described herein, canbe determined through experiments and testing, as a particular device orsystem is being developed under the principles of the invention, toapply to a particular applications.

In order to help determine the optimum specifications when designing aNitrafix system, the following formulae may be used for calculating theflow rate through the system, volume of media in each of the chambers ofthe system, and the time for treating 99.99% of water in a recirculatingsystem.

The desired flow rate can be determined according to the formula I,F=V _(t) /A  (I)where

-   -   F is flow rate in gallons per hour,    -   V_(t) is the volume of water (in gallons) in the aquarium to be        treated per hour, and    -   A is an experimentally determined coefficient having a value        which depends on a number of variables, including the nitrate        level of the water, the quality of the filtration, and the        volume of water to be treated. The greater the nitrate level,        the greater the value for A. The value of A may range, for        example, from 30 to 200. To simplify the calculations and avoid        experimentation, a value of 100 may be used for aquariums having        a volume of water of under 10,000 gallons, although the value        for A may be determined experimentally if greater precision is        desired. Generally speaking, larger systems may have values        lower than 100, such as from 20 to 50, although the exact value        for these larger systems will generally be determined        experimentally.

The volume of media in section 108 of each of the chambers may becalculated according to formula II,V _(m) =V _(t) /N  (II)where

-   -   V_(m) is volume of media in the chambers    -   V_(t) is volume of water in the aquarium to be treated    -   N is an experimentally determined coefficient having a value of        from 100 to 500, depending on the volume of water to be treated        (V_(t)) and the amount of food added to the tank, or TAN. For a        typical fish tank up to 10,000 gallons, N may be chosen to        be 200. The value for N may increase for larger aquariums or for        aquariums with fewer fish. The value for N may decrease for        aquariums with large numbers of fish.

In one example, nitrates are calculated to be reduced in saltwater byapproximately 100 ppm in one cycle using a pastille shaped sulfur mediahaving a surface area of 11.36 cm²/g, and a volume of media calculatedusing a value of N=400, which was randomly chosen for the purpose ofthis example.

The formula for determining the time it would take to treat 99.99% ofthe water in a recirculating system (i.e., the length of time per cycle)is determined byT=9.2V _(t) /F _(o)where

-   -   T is the amount of time per cycle (in hours),    -   V_(t) is the volume to be treated in gallons, and    -   F_(o) is the flow through the sulfur in gal/hour.

Before the water being treated by the embodiment of FIG. 8 is returnedto the aquarium tank, it is preferable to add oxygen to the water,especially for large aquariums of, for example, 10,000 gallons or more.A degassing chamber, such as a protein skimmer or other conventionaldegassing chamber, may be used to accomplish this. One example of anovel protein skimmer which may be used will be discussed below in thedescription of FIGS. 20 to 22. Additionally, the oxytower, as discussedabove, may also be used to add oxygen to the water.

Another preferred embodiment is illustrated in FIG. 15, which shows asystem comprising multiple sections arranged vertically through a singlechamber 500. The sections are separated by perforated plates 503.Section 510 is an empty space through which water entering the chambercan flow. Section 520 contains a media capable of supporting aerobicbacteria, such as the aerobic bacteria previously described herein.Section 530 contains sulfur media capable of supporting anaerobicbacteria, such as the anaerobic bacteria previously described. Sections540 and 550 both contain calcium media. The calcium media in section540, which is the calcium chamber nearest the inlet, contains arelatively less soluble media compared to the calcium media contained insection 550. Both sections 560 and 580 preferably contain activatedcarbon media, which traps undesirable contaminants, such as hydrogensulfide gases, which may be produced during the process. Section 570 isleft empty to allow for easy flow of water out of the system 500.

Water flows through inlet 516 down pipe 513 and through pipe 501, upthrough system 500 and exits through pipe 511. Exhaust gases generatedduring the process can exit system 500 through exhaust vent 550. Tubing517, extending up from exhaust vent 550, may optionally be used to raisethe level to which the water must rise before overflowing out of thesystem. A portion of clear pipe may optionally be used to allow forvisual inspection of the system. For example, clear pipe section 513and/or clear pipe section 514, as illustrated in FIG. 15, may be used toconnect the inlet pipe 501 and the exhaust pipe 550 to either end of a Tpipe junction 516. Generally, any type of clear pipe may be used. Forexample, glass or clear plastic, such as clear PVC, may be used for theclear pipe sections. The upward flow of water through system 500 helpsto prevent clogging.

The dimensions of the chamber 500 can vary according to the requirementsof the aquarium. The chamber 500 may have, for example, a cylindricalshape. In one embodiment, chamber 500 is a PVC pipe having a diameter ofapproximately 4 inches and a length of approximately 20 inches, witheach section having the following approximate lengths:

-   -   Empty space, section 510—1.5 inches    -   Media for aerobic bacteria, section 520—2.5 inches    -   Sulfur media, section 530—4 inches    -   Hard calcium media, section 540—3 inches    -   Soft calcium media, section 550—3 inches    -   Activated carbon media, section 560—2.5 inches    -   Empty space, section 570—1.5 inches    -   Activated carbon, section 580—2 inches.        The total weight of this 20 inch embodiment is approximately 12        pounds. It can be used for an aquarium having a volume of up to        about 120 gallons of water. In certain applications, this        embodiment can be a disposable unit that can be thrown away. In        other applications, the media in the system can be replaced as        needed. The diameter and length of the chamber and the lengths        of the sections 510 to 580 could be increased or decreased, as        desired, in order to treat larger or smaller aquariums.

FIG. 12 a illustrates another embodiment of the present invention. Asshown in FIG. 12 a, the system comprises a biological system 400comprising an outside container 402 divided into various chambers orcartridges, as illustrated by perforated walls 403. The outsidecontainer may be made of a plastic material, such as acrylic, forexample. The material may be opaque, such as black colored plastic. Thechambers containing the media may also be made of plastic, such aspolyethylene or polypropylene.

System 400 is generally for use with smaller aquariums, such as thosehaving 5 to 50 gallon tanks. However, it may be used for larger systems,as well. It is designed to hang on the aquarium tank wall, having bothan inlet 401 and an outlet 411, which can extend over the tank wall anddown into the aquarium, as shown in FIG. 13. For residential aquariums,a system according to this embodiment could be configured in adisposable unit that can be purchased in a closed configuration with allof the elements and components in the unit. Such disposable units mayhave a life in the range of about 1 to 2 years, for example, dependingon the life of the media used therein.

The denitration chamber 420 is filled with a sulfur media, such as anyof the sulfur media previously described above. Calcium chamber 430 isfilled with one or more calcium sources, such as any of the calciumsources described above. In a preferred embodiment, chamber 430 isfilled with a mixture of aragonite, dolomite and calcite. Alternatively,the chamber may be filled with only one or two of these sources ofcalcium, rather than all three. The denitration chamber 420 and calciumchamber 430 function to remove nitrates, add calcium and control pH,similar to the denitration chamber and calcium chambers of the abovedescribed embodiments.

Both chambers 410 and 440 may remain substantially empty, except for theflow of aquarium water. Water flows into chamber 410 through inlet 401.Water then flows from chamber to chamber through perforated walls 403,first flowing through denitration chamber 420, calcium chamber 430, andthen into chamber 440. In order to force water through the system, airis pumped through air hose 460 into outlet conduit 411, which extendsdown into chamber 440. The air bubbles rising up through outlet conduit411 force water up and out of the system. Other systems known in the artfor moving water through system 400 may be used instead of the air pump,such as, a minni-pump, for example.

Chamber 407 is filled with activated carbon, which acts to removehydrogen sulfide gas odors produced in the denitration chamber. Gasesemitted from the system can rise through the perforated plates 404 andleave the system through vents 450.

Another embodiment is shown in FIG. 12 b. This embodiment is similar tothe embodiment described above for FIG. 12 a, except that a chamber 415,which is filled with a media for supporting aerobic bacteria, is addedbetween chambers 410 and 420. The media in chamber 415 may be any mediacapable of supporting aerobic bacteria, such as, for example, crushedcoral or biofilm. This purpose of chamber 415 is to remove oxygen andreduce ammonia to nitrite and nitrite to nitrate, similar as describedabove with respect to the aerobic chamber 110 for the embodiment ofFIGS. 2 and 8.

Another embodiment of the present invention is the application of theinvention to large fresh and salt water aquariums having a volume of,for example, 10,000 gallons or more. As with the other Nitrafix systemsdisclosed herein, this embodiment of the invention could be applied toboth fresh and salt water aquariums, as well as brackish wateraquariums, and makes it possible to create a working salt water aquariumin an inland location that does not have another available source toreplace all or part of the salt water in the aquarium, as is done understandard systems for large salt water aquariums. Such a system is showngenerally in FIG. 17.

As shown in FIG. 17, water from the aquarium is first supplied to achamber 610 that supports the colonization of aerobic bacteria thatreduce ammonia and nitrites in the water and increase concentrations ofnitrates. For example, a sand filter or a floating bed reactor filter,both of which are well known in the art, may be used as chamber 610.Examples of specific sand and floating bed filters which may be usedinclude a bead filter, from aquaculture systems technologies, and sandfilters from Jacuzzi. These filters would both filter out unwantedmaterial from the water and also support the aerobic process of reducingammonia and nitrites in the water while increasing nitrates and at thesame time increasing CO₂ concentrations and reducing or eliminatingdissolved oxygen in the water. As previously explained, the aerobicbacteria chamber will increase efficiency of the denitration process bythe anaerobic bacteria and reduce the amount of bacteria and sulfurneeded in the second chamber.

One embodiment of a novel aerobic chamber which may be used in thesystem of FIG. 17 will now be described with reference to FIG. 24.Chamber 610 comprises a tank 108. The lower portion of tank 108preferably has a tapered shape to collect sediment which settles to thebottom, although it may have a flat bottom. A drain 326 a and valve 326b can be included in the bottom of 610, to allow sediment to beperiodically removed. If desired, a clear section of pipe 326 c may beemployed to allow visual inspection of the drain so that sedimentbuildup may be monitored. A lid 106 may be used to cover the tank 108.Chamber 610 should be relatively air tight, so that the level of oxygenin the water may effectively be reduced by the aerobic bacteria. A vent113 having a check valve 114 may be used to vent gases from the chamber,but will preferably not allow substantial amounts of outside air intothe chamber.

The chamber has an inlet 111 and an outlet 121 through which water canenter and exit the chamber. A screen 101 may be placed over the outletand inlet to avoid clogging and contain the media within the chamber.The height H1 of the inlet pipe 111 a will control the level of water inchamber 610.

Section 108 of chamber 610 may be partially or completely filled withsupport media 112, which acts as a substrate for the aerobic bacteria.The aerobic bacteria already exist in the water of the aquarium and willreadily colonize on the media. The media 112 may be any type of mediathat can support colonization of aerobic bacteria. While a media havingany practical size and shape may be used, media having a high surfacearea is preferred. For example, sand, crushed coral and other mediahaving relatively high surface areas may be used. One preferred form ofsupport media is plastic, which may be in the form of small spheres ortubes, although any shape known in the art may be used. The plasticmedia is lightweight and may float in the aquarium water. It does notclog easily, and provides a large surface area for bacterialcolonization. One example of such a plastic media is known as biofilm.One particular type of biofilm is manufactured by Water ManagementTechnologies, Inc. under the name of Kaldnes or Bee-Cell. Other medialike Bio-Chem stars from RENA may also be used. If media 112 does notfloat, a perforated plate or screen 115 may be employed to hold themedia above the cone shaped bottom, to allow a space for sediment tosettle in the tank.

As shown in FIG. 17, the system preferably includes a plurality ofanaerobic denitration chambers 620 which are placed in parallel flowwith each other. Alternatively, the chambers may be placed in series,where water flows from one denitration chamber to the next. Each chambermight, for example, be a cylindrical chamber having a diameter rangingfrom about 6 inches to about 10 feet and height ranging from about 8 toabout 20 feet. The chamber may be sized so that it can be readilypositioned in the basement of the aquarium facility, or at some otheracceptable location. These chambers can be placed in different locationsrelative to the aquarium, even including locations significantly remotefrom the aquarium itself. As the application previously explained,anaerobic bacteria within the chambers reduce nitrate concentrations.

Preferably the denitration chambers either include a degassing material,or provides an outlet for allowing exhaust gases produced during thedenitration process to flow to a separate chamber containing degassingmaterial, in order to eliminate the odor from noxious gases, such ashydrogen sulfide, which may be produced during the denitration process.The degassing material may be, for example, activated carbon.

Examples of denitration chambers that may be used for large aquariumsare illustrated in FIGS. 9 and 11 and will now be described. Where largeamounts of sulfur media are used to treat the aquarium water, the sulfurmay crush itself by its own weight in the lower parts of the chamber andcause clogging. In order to avoid clogging, as well as to increase theefficiency of the biological system, a denitration chamber 220 accordingto an embodiment illustrated in FIG. 9 may be used. As shown in FIG. 9,the sulfur media 122 is placed on shelves 223 within the chamber. Theshelves are perforated in order to allow water to flow through thechamber. The chamber bottom 225 has a tapered shape to collect sediment.A drain 326 a and valve 326 b can be included in the bottom of chamber120, to allow sediment to be periodically removed. If desired, a clearsection of pipe 326 c may be employed to allow visual inspection of thedrain so that sediment buildup may be monitored. The chamber has aninlet 211 and an outlet 221 through which water can enter and exit thechamber.

FIG. 11 illustrates another denitration chamber embodiment, whichutilizes floating balls comprising sulfur. FIG. 10 shows a floating ball322 comprising sulfur, according to one embodiment of the presentinvention. The balls have a density that is less than that of water, andtherefore float in the water. The balls may be hollow plastic orStyrofoam balls which are filled with a mix of sulfur media and plasticor Styrofoam media. Holes 323 in the balls allow water to flow into andout of the balls and contact the sulfur media contained therein. Theballs and the media contained in the balls may be any workable size orshape. For example, the balls may have a diameter of 1½ to 3 inches with⅛ to 5/32 inch diameter holes drilled therein. The media within theballs may have a diameter of, for example, ⅛ inch to ¼ inch.

The floating balls comprising sulfur are placed in a chamber, such aschamber 320 illustrated in FIG. 11, for example. The chamber shown inFIG. 11 is a cylinder having a conical shaped bottom 325, in order tocollect sediment. Clear tubing 326 may be placed at the tip of thechamber bottom 325 in order to allow for visual observation of sedimentwhich may be collected. Valve 327 allows the sediment to be drained fromthe chamber bottom when necessary. Chamber 320 may be made of, forexample, PVC, polyethylene, polypropylene, methacrylic or acrylicplastic, fiber glass reinforced plastic (FRP), or stainless steel. Aninlet 311 may be placed near the bottom of the chamber and outlet 321near the top, so that the aquarium water flows up though the sulfurcontaining media and exits the chamber through outlet 321. A gas outlet324 is placed in the top of chamber 320 to allow gases produced in thechamber to escape. The exhaust gases may then be flowed throughactivated carbon, in order to remove hydrogen sulfide gas, before beingreleased into the atmosphere.

Chamber 320 is filled with the floating sulfur media. For example, ½ to¾ of the volume of the tank may be filled with the floating sulfur balls322. A backwash pump 328, which pumps water out of the chamber and thenreturns it to the chamber through a conduit having an outlet in closeproximity to the floating balls, may be used to wash the balls.Alternatively, an injector (not shown) may be used to inject carbondioxide gas into the chamber to wash the balls. Washing the balls mayhelp to remove any particulate matter that can build up on or betweenthe balls. Such build up can undesirably reduce the flow of waterthrough the holes in the balls, as well as through the chamber itself.Additionally, the backwash pump or injector may increase contact timebetween the sulfur surface area of the balls and the water being treatedby increasing the circulation of balls inside the chamber. Additionally,the motion of the balls caused by the backwash pump or injector may helpgases that form inside the balls during the process to be discharged,which allows more water to enter the balls, thus increasing contact timeof the sulfur with the water.

After denitration occurs in the system disclosed in FIG. 17, water canthen be directed to flow through one or more calcium chambers 630 orother chambers or systems to increase the pH of the water and addappropriate minerals for the health of sea life and coral within theaquarium.

One example of a calcium chamber which may be used for large aquariumsis shown in FIG. 25. Where large amounts of calcium media are used totreat the aquarium water, the calcium may crush itself by its own weightin the lower parts of the chamber and cause clogging. In order to avoidclogging, as well as to increase the efficiency of the system, a calciumchamber 630 according to an embodiment illustrated in FIG. 25 may beused. As shown in FIG. 25, the calcium media 632 is placed on shelves633 within the chamber. Various sources of calcium may be used, such asaragonite, calcite and dolomite, as described above in connection withthe other embodiments of the Nitrafix. If multiple sources of calciumare used, it may be preferable to place the harder to dissolve calciumon the bottom shelves and the more easily dissolved calcium on the uppershelves, in order to extend the life of the calcium media. The size ofthe media may be any practical size known in the art. For example, thesize may range from 3 to 10 mm in diameter.

The shelves are perforated in order to allow water to flow through thechamber. The chamber bottom 635 preferably has a tapered shape tocollect sediment and small particles of calcium which fall through theperforations in shelves 633, although it may have a flat bottom. A drain326 a and valve 326 b can be included in the bottom of chamber 630, toallow sediment and calcium to be periodically removed. If desired, aclear section of pipe 326 c may be employed to allow visual inspectionof the drain so that sediment buildup may be monitored. The chamber hasan inlet 631 and an outlet 641 through which water can enter and exitthe chamber. A lid 636 may be used to cover the chamber.

Other systems may also be used for large aquariums. For example, waterfrom the denitration chambers can be directed to one or more of thefollowing systems, in addition to or in place of a calcium chamber orchambers: a protein skimmer 650, a degassing tower 660, an oxytower 670,and a desulfator 680. While protein skimmer 650, degassing tower 660,oxytower 670, and desulfator 680, are being described here in connectionwith the embodiment of FIG. 17 for use with large aquariums, they arealso contemplated for use with aquariums of any size, including homeaquariums of 50 gallons or less.

A novel protein skimmer will now be described in connection with FIGS.20 a to 20 c. The purpose of the protein skimmer is to removecontaminants, such as undesirable organic matter, otherwise known asdissolved organic compounds (DOC), from the water, as well as toincrease the oxygen level of the water. Protein skimmer 650, as shown inFIG. 20 a, includes a mixing chamber 651, a collecting cup 652, a mixingeductor 653, and a bowl shaped cup 655. The protein skimmer of FIG. 20 ais preferably used for salt water applications where the water has aspecific gravity greater than about 1.020, although it may also be usedfor fresh water applications.

Water flows into mixing chamber 651, which remains substantially filledwith water during processing, through inlet 654. The water in the mixingchamber is circulated using pump 656, which draws water from the chamber651 through pipe 658 and forces the water through eductor inlet channel653 a. Alternatively, the water going to eductor inlet channel 653 acould be supplied from a source outside chamber 651, such as from thesump or the aquarium itself. Water passing through the eductor mixingchannel 653 b is mixed with an oxygen containing gas, such as air,oxygen gas, ozone, ionized gas, or a mixture thereof. Using a gascomprising ozone will make the system more efficient and reduce oreliminate sulfate. The oxygenated stream of water, having bubblescomprised of the oxygen containing gas, flows out of the eductor anddown into chamber 651 against concave surface 655. Concave surface 655,which may have cup or bowl shape, then redirects the stream of water andbubbles upward into the mixing chamber. As the bubbles rise in thechamber, undesirable contaminants attach to the bubbles and rise to thesurface, where they are captured in the collecting cup 652 and disposedof. The eductor 653 allows for a relatively large amount of gas to bemixed into a liquid using a relatively small amount of power. Anenlarged view of eductor 653 is shown in FIG. 21 a. The mixing channel653 b comprises a flared inlet region 653 f and a flared outlet region653 g, which are connected by a generally cylindrical shaped neck region653 e.

The inlet channel 653 a of the eductor, which may be, for example, anozzle, is located near the flared inlet of the mixing channel 653 b, sothat a central longitudinal axis of the inlet channel 653 a is alignedalong the central longitudinal axis of the mixing channel 653 b, in amanner which allows water from the chamber 651 to be entrained throughthe opening 653 d between the outside of the inlet channel and theinside of the flared inlet region of the mixing channel. To beefficient, the stream of water from inlet 653 a preferably entrains arelatively large amount of water from chamber 651 as it flows intomixing channel 653 b, so that the flow of water through the channel 653b is significantly greater than the flow from inlet 653 a. For example,as illustrated in FIG. 21 b, the flowrate “B” of water entrained may be3 to 6 times greater, and is preferably 4 times greater, than theflowrate “A” from inlet 653 a. The flowrate of water exiting the eductoris thus “A”+“B.” In this manner, the use of the eductor in the proteinskimmer allows for a relatively large volume of water to be mixed withgas utilizing a relatively small amount of power.

Additionally, the use of the eductor will increase the contact timebetween the gas bubbles and the liquid by providing improved mixing ofthe bubbles with the water, which may allow the skimmer of the presentinvention to be smaller and more efficient than conventional proteinskimmers.

As shown in FIG. 21 b, the tubing 653 c is positioned in the flow ofwater through channel 653 b at an angle θ_(t) from the centrallongitudinal axis of channel 653 b. Adjusting the angle θ_(t) has beenfound to provide for improved entrainment and mixing of the gas with thewater. While the angle θ_(t) may range, for example, from 0 to 90°,θ_(t) preferably ranges from 30 to 60°, and is more preferably about45°. The angle of the tube opening θ_(o), as illustrated in FIG. 21 b,may also be adjusted to provide for improved entrainment. For example,the angle θ_(o) may be adjusted from 90° to 135°. The tubing extendsinto the flow path of the mixing chamber, preferably so that the outletof tubing 653 c is preferably located at or near the centrallongitudinal axis of the mixing channel 653 b. The diameter of thetubing may be adjusted to allow more or less gas into the mixingchannel, without undesirably interfering with the flow through thechannel. For example, the tubing may have a diameter ranging from ⅛ inchto 1 inch. The water flowing past the tubing 653 c creates a suction,thus causing the fluid in tubing 653 c to be sucked from the tubing andinto the mixing channel 653 b.

The mixing eductor, including the nozzle, mixing chamber and tubing maybe made of various materials, such as plastic or metal. Specificexamples of such materials include PVC, polyethylene, polypropylene,methacrylic or acrylic plastic, fiber glass reinforced plastic (FRP), orstainless steel. Any other materials, known in the art for makingeductors, may also be used. The mixing eductor is contemplated for usein other applications. For example, rather than a gas, a liquid may beflowed through tubing 653 c, so that multiple liquids may be mixedtogether. Additionally, more than one tube 653 c may be positioned inthe mixing channel. For example, mixing eductors having two, three, fouror more tubes positioned in the mixing channel in a manner similar totube 653 c are contemplated. A 3-dimensional view of an embodiment ofthe eductor is illustrated by FIG. 21 c.

Another embodiment, which is preferably used for fresh waterapplications, is shown in FIG. 20 b. This embodiment is similar to theembodiment of FIG. 20 a, as described above, except for the dimensionsof the eductor, and the concaved surface 655. As shown in FIG. 20 b, thelength of the outlet cone 653 g is longer than the eductor used in theembodiment of FIG. 20 a, and may range, for example, from about 1 inchto about 80 inches long, and may more preferably be from about 20 toabout 60 inches long. In addition, the angle, θ_(f), of the outlet conemay be adjusted so that the cone encompasses a relatively large volumeof water in the chamber. For example, the angle, θ_(f), may be rangefrom about 1° to about 60°, and may more preferably be from about 30° toabout 45°. The larger cone acts to trap gas bubbles, which are forcedupward by the concave surface 655, so that the bubbles are not allowedto rise to the surface, but remain trapped between the cone and thesurface 655, where the water is well mixed and the bubbles will beforced to circulate through the water. This increases the contact timeof the bubbles with the water before they finally escape from underneaththe cone, thereby increasing the amount of organic matter trapped by thebubbles. If necessary, the size and shape of the concave surface 655 mayalso be adjusted to reduce the space “L” between the surface 655 and theend of cone 653 g, in order to more effectively trap the bubblesunderneath the cone. For example, L may range from about ¼ inch to about60 feet, and may more preferably be from about 8 inches to about 10feet.

The longer contact time is especially important for fresh water, as thebubbles formed in fresh water are naturally smaller than the bubblesformed by the eductor in salt water, which effectively decreases thetotal surface area of the bubbles formed in fresh water, thus decreasingthe efficiency of the skimmer. This difference in bubble size is thoughtto be caused by the different specific gravities of salt and freshwater. In any case, the increased contact time of the bubbles in theFIG. 20 b application helps to compensate for the decrease in totalsurface area of the bubbles in fresh water. However, the embodiment ofFIG. 20 b is not limited to fresh water, but may be used any timeincreased contact time between the bubbles and the water is desired.

In yet another embodiment, illustrated in FIGS. 22 a and 22 b, theoutlet cone 653 b of the eductor may be modified by adding wings, orfoils, 653 d to the inner surface of the outlet cone. The foils rotatearound the inside surface of the outlet cone in a manner which act todirect the motion of the water through the cone in a helical path, thuscreating a vortex. Such a circular motion may act to increase thecontact time of the bubbles with the water, and thereby increase theefficiency of removal of organic matter in the water. The dimensions ofthe foils may be modified to be any size or shape which will create thedesired circular motion. For example, the foils may extend from about1/16 to about 1 inch from the inner surface of the cone for the entirelength, or only a portion of the length, of the outlet cone 653 d, andmay have and a width of from about 1/32 to about ⅛ inches.

Embodiments using multiple eductors in a single tank are alsocontemplated, as shown in FIG. 20 c. The eductors may be arranged bothvertically and/or horizontally within a tank in order to provide thedesired circulation of bubbles for any given shape or size of tank, tomaximize removal of organic matter.

While the novel protein skimmer's described above for use in the systemfor large aquariums, as illustrated by FIG. 17, the protein skimmer's ofthe present invention may be used in any system where a protein skimmeris desired. For example, the protein skimmer's of the present inventionmay be used in combination with any of the other nitrafix systemsdisclosed herein. The flow through the protein skimmer may be optimizedto achieve the desired water quality. For example, the flow rate throughthe skimmer may be from 1 to 3 times the aquarium volume per hour.

The eductor of the present invention is contemplated for use in otherapplications besides a protein skimmer where up to three differentfluids are to be mixed.

Referring back to FIG. 17, another alternative embodiment provides forflowing water from the anaerobic chambers to a conventional degassingtower 660 which puts oxygen into the water and raises the pH. In adegassing tower, water cascades down through plastic balls or over ascreen, breaking up the water and increasing the surface contact of thewater with air, thereby entraining air into the water. Such degassingtowers are well known in the art.

In yet another embodiment, water from the anaerobic chambers is suppliedto an oxytower 670 of the present invention, which is illustrated inFIGS. 18 a and 18 b. The oxytower removes nitrates, nitrites,phosphates, carbon dioxide and heavy metals from the water, as well asadds oxygen to the water. By oxygenating the water, the pH will remainmore stable than water that is oxygen deficient. Further, the oxytowerwill also help to cool the water by evaporation.

The oxytower of the present invention is in the shape of an invertedtruncated cone, having side walls 671 a that slope inward at an angleθ_(oxy) of, for example, 5 to 45 degrees, and more preferably 10 to 20degrees, as shown in FIG. 18 a. A medium, such as a screen 672, isplaced on the inner surface of the cone and serves as support for thegrowth of algae in the oxytower. A pipe 675 a or other means, such as agutter, for channeling water is located along the top innercircumference of the oxytower chamber. The pipe 675 a has a plurality ofoutlets 676, such as holes or jets, located along its outercircumference through which water may be dripped or sprayed along thetop surface of the screen. The pipe 675 a is connected onto the wall ofthe oxytower by supports 675 b, as shown in FIG. 18 b. An artificiallight 673 is applied to support photosynthesis by the algae growing onthe screens. Alternatively, the oxytower may be placed so it issubjected to sunlight during the day.

During operation of the oxytower, water flows into pipe 675 a throughinlet 674, and is dripped or sprayed from outlets 676 onto the top ofthe screens 672. The water then drips down the screens by force ofgravity. As the water drips down the screen surface, the screen willbreak up the water and cause an increase in surface area, which willallow for the water to be effectively degassed. Additionally, algaegrowing on the screens will remove unwanted contaminants in the water,such as phosphates, nitrates, nitrites and heavy metals, which the algaeuses for nutrients as it grows. The water then flows out of the towerthrough outlet 677. Water from the outlet may be passed through straineror mechanical filter 678 a for removing debris from the water. As shownin FIG. 18 a, a trap basket 678 b may be used for holding the removeddebris.

The flow of water through the tower may vary. For the oxytower to beeffective, it is preferable that the volume of water being treated passthrough the oxytower 2.5 times per day. It is more preferable that thevolume of water being treated pass through the oxytower once per hour.

While the walls of the oxytower are preferably inclined, as shown inFIG. 18 a, the walls, as well as the screens supported by the walls, maybe vertical, so that the oxytower has a cylindrical shape. The walls ofthe oxytower can be made of any neutral plastic (i.e., a plastic that isminimally reactive, or non-reactive, with the water being treated) thatis safe for aquatic life. Examples of suitable materials include PVC,polyethylene, polypropylene, methacrylic or acrylic plastic, fiber glassreinforced plastic (FRP), or stainless steel. The oxytower may have adiameter of up to 8 feet or more, and may have any practical height.

The screen 672 may be made from any material which is safe for aquaticlife and which is resilient and will not corrode in saltwater. Forexample, the screen may be made of soft nylon or fiberglass material.The screen may be one continuous piece, but is preferably in multiplepieces for easy cleaning. For example, the screen may have 4, 6, or 8sections. The screen may have various shapes, sizes and hatchingpatterns. The preferred screen would have a diamond shape cross hatchingthat is 3/16 inch to ¼ inch in length for each leg of the diamond. Thescreen, or screen sections may be attached to a pre-formed plasticsupport. The plastic support can then be attached to the inside of thetower. Alternatively, a medium other than screens may be used which willaccomplish a similar function as the screens. For example, carpet may beused in place of the screens.

During operation of the oxytower, the screens should periodically becleaned in order to promote the optimal growth of algae for removingcontaminants from the water. It is preferable that the entire surfacearea of the screen not be cleaned at one time. For example, in anembodiment where there are 4 sections of screen, it is preferable thatmore than 2 sections not be cleaned at one time. For best results, thescreens are cleaned periodically on a rotating bases, where one screenis cleaned, and then after the algae begins to grow on the cleanedscreen, another screen is then cleaned. The cleaning of the screensshould be done carefully so as not to remove the roots of the algae. Ifthe roots are removed, the algae will grow more poorly and slowly.Preferably, the screens should not be bleached, pressure cleaned orcleaned with chemicals, so as not to harm the algae.

The light source 673 may be any light source which will provide thenecessary light for photosynthesis and algae growth. The light sourcemay be natural or artificial light and may be provided either directlyor indirectly to the algae. For example, where the surface of the screenis 2 square inches per gallon of water to be treated, and the flow ofwater is 0 to 0.02 gal/min/square inch of screen surface, the lightsource preferably provides at least 0.75 watts per 10 in² of screensurface, such as, for example 1 watt per 10 in² of screen surface.Examples of light sources which may be used include natural sunlight, apower compact tube, a high output (HO) or very high output (VHO)fluorescent bulb with a spectrum of 4000 K to 10,000 K. A metal halidebulb may also be used. Bulbs may be mounted vertically and continuouslyalong the height of the oxytower. The light source 673 should be placeda distance from the screens which will be effective for promotingphotosynthesis and growth of the algae. For example, where the above HOor VHO fluorescent bulbs are used in the embodiment of FIG. 18 a, thetower preferably has a maximum diameter of from 4 to 8 feet, in order tooptimize the distance from the screens to the light. For larger units,metal halide bulbs may be used with or without reflectors. It ispreferable that the light remains on 24 hours per day continuously foroptimal algae growth.

The bulbs can be covered with a translucent acrylic or glass covering toprotect them from water. In larger units the protective covering 673 bwill preferably extend all the way through the unit and will haveopenings 673 c and 673 d to allow for improved ventilation, as shown inFIG. 19 a. The heat produced from the light will rise, which will causean elevated air current to suck in cool air from the bottom opening 673c of the protective covering 673 b and cool the light bulb 673 a. Anapparatus for moving air, such as a fan (not shown), can be added tofurther ventilate the light to make cooling more efficient.

In another embodiment, illustrated in FIG. 19 b, a stainless steel bar673 e can be used for support for multiple bulbs 673 a. In thisembodiment, the number of lights may be chosen to optimize the amount oflight for improved algae growth and contaminant removal from the water.

The oxytower may have a top cover 671 c, to prevent unwanted debris fromgetting inside. The cover may be transparent to allow light, such asnatural sunlight, into the chamber. The cover may have a chimney 671 dthrough which gas emissions from the oxytower may be collected and/orvented. For example, the chimney may be filled with activated carbon,which may be used to adsorb hydrogen sulfide gas.

The bottom of the chamber 671 b may be flat, or it may be conicallyshaped as shown in FIG. 18 a. The conical shaped bottom 671 b is betterfor collecting detritus.

An optional blower 679 may be used to blow air into the oxytower, whichwill increase evaporation in the tower and cool the water, as well ashelp to degas the water. If a blower is to be used to cool the water, itis preferable that the tower be insulated for improved coolingefficiency. Additionally, carbon dioxide may also be blown into theoxytower to raise oxygen levels in the water through increasedrespiration and production of oxygen by the algae.

The oxytower of the present invention is particularly suited for use incombination with at least aerobic and anaerobic chambers of the presentinvention, to treat and condition water in aquariums of 500 gallons ormore. However, the oxytower may be employed for smaller aquariums andmay be used in combination with any of the systems described herein. Inaddition, the oxytower of the present invention can be applied to otherapplications where water is to be treated, even in the absence of thedenitration methods and systems of the present invention. For example,the oxytower can be used in place of protein skimmers in standardcommercial applications.

Additionally, the oxytower is contemplated for use in a broad range ofother applications, such as for use in waste water treatment, drinkingwater purification, and other applications where it would be helpful toremove contaminants using algae.

A further process step, which may be added to any of the Nitrafixsystems described herein, can be used to reduce sulfate concentrations.As described above, the denitration process of the systems of thepresent invention results in increased levels of sulfates in the water.Additionally, there is the possibility that undesirable amounts ofhydrogen sulfide may also be produced at certain times, such as atstartup, after the denitration chamber has been shut down for a periodof time. Consequently, it may be desirable in some aquarium systems toreduce the level of sulfates and/or hydrogen sulfide.

Accordingly, a novel method and desulfator apparatus for reducingsulfate and hydrogen sulfide concentrations in aquarium water will nowbe described with reference to FIGS. 23 a to 23 c. The method andapparatus are not limited to use with the systems of the presentinvention, but could be used in any system where it is desirable toreduce sulfate concentrations.

The desulfator of the present invention utilizes anaerobicphotosynthetic bacteria to reduce sulfate levels in both fresh andsaltwater systems. Any type of anaerobic photosynthetic bacteria whichwill reduce sulfate levels may be used. Examples of such bacteria mayinclude, purple bacteria, purple nonsulfur bacteria, and/or green sulfurbacteria, such as Chromatium vinossum, Thiospirillum jenense,Rhodospirillum rubrum, Rhodobacter sphaeroides, Chlorobium limicola,Prosthecochloris aestuarii. In the presence of light, these bacteriawill use photosynthesis to break down sulfates and/or other sulfurcompounds in the water.

One preferred embodiment of a desulfator apparatus 680 is illustrated inFIG. 23 a. The desulfator apparatus of this embodiment preferablycomprises a chamber 700, which contains media 703 for supporting thesulfur bacteria, a light source 702, as well as inlet 701 and outlet704, for allowing water to flow in and out of the chamber.

The chamber 700 can be any shape, but is preferably a cylindrical shapedchamber having an outer cylinder 705 and an inner cylinder 706concentrically arranged inside the outer cylinder. The walls of thechamber are preferably transparent to light, and may be made of, forexample, a clear acrylic plastic. The media 703 for supporting thebacteria is contained between walls 705 and 706, as illustrated in FIG.23 b. The portion of the chamber containing the media should be airtight, so as to not allow the introduction of oxygen into the chamber. Avent 710 having a valve 711 may be used to allow exhaust gasses producedwithin the chamber to escape. Valve 711 is a one way flow valve,allowing the flow of gases out of, but not into, the chamber.

The support media 703 is preferably transparent to light. For example,the media may be a clear biofilm, such as, Kaldnes, which is made byWMT. Other media like Bio-Chem stars from RENA may also be used. Thesurface area provide by the media is preferably relatively large. Forexample, the media may have an average surface area of 500 square metersper cubic meter or greater, and more preferably an average surface areaof 850 square meters per cubic meter or greater.

The ratio of the height of the chamber to the diameter of the chamber ispreferably from 3 to 5, in order to allow for sufficient contact timebetween the water and the bacteria supporting media.

The light used in the chamber can be either natural sunlight orartificial light, or both. For example, a light source 702 a may extenddown through the inside of cylinder 706, as shown in FIGS. 23 d, 23 eand 23 f, in order to provide light throughout the chamber. FIG. 23 dillustrates the use of an HO or VHO tube, which must be connected to apower source at both ends 702 b and 702 c. FIG. 23 e illustrates the useof metal halide or incandescence bulbs 702 b, which may be arrangedvertically down the center of the chamber as shown, in order to providethe desired amount of light to the bacteria. FIG. 23 f illustrates thususe of a power compact tube 702 b, which has the advantage of beingconnected to the power source at only one end. The cylinder 706 may beopen at its ends in order to allow for ventilation to the light source,as shown for example in FIG. 23 d. An apparatus for moving air, such asa fan 713, as illustrated in FIG. 23 e, may be used with any of thedisclosed light sources to increase the amount of ventilation throughthe cylinder 706.

Because the walls 705 and 706 and the media 703 are transparent to thelight from the light source, a maximum amount of the volume of thechamber housing the bacteria is exposed to the light, thus increasingthe efficiency of the chamber. The spectrum of light used is preferablya day spectrum light from 4000° K to 25000° K. The light may be left oncontinually for increased efficiency.

The flow of water through chamber 700 is preferably from bottom to top,in order to avoid clogging. Additionally, as shown in FIG. 23 c, screens712 may be placed in front of the inlet 701 and outlet 704 to preventclogging and to contain the media in the chamber. The flow rate of waterthrough the chamber may be adjusted to allow for the desired amount ofsulfate reduction. Because the bacteria used in the desulfator apparatusare anoxygenic, it is preferable that the water entering the chamberhave a low oxygen content. If necessary, a system for reducing oxygencontent of the water may be utilized to reduce the oxygen concentrationbefore the water enters the chamber.

Yet another preferred embodiment of a system for filtering andconditioning water will now be described with reference to FIG. 26.While the system is designed for use with larger aquariums, it may beused for any size aquarium. The system may also be used for maintainingthe water of aqua tanks, where fish are raised in aqua cultureapplications.

Water flows from aquarium or aqua tank 116 to a filter 101. This filteris preferably a mechanical filtration device which allows the water topass through the filter without pressurization from a filter pump, thussaving power. However, any filter known in the art may be used,including filters requiring a filter pump. The filter removesparticulates from about 30 microns to about 200 microns from the water.Examples of filters which are known in the art include a drum filter, adisk filter, and a sock filter.

Water next flows from filter 101 to a sump 102. Sump 102 preferably hasa volume which is large enough to prevent overflow of water from thesystem when the system is stopped. Both mechanical filter 101 and sump102 may be placed at elevations which are lower than aquarium or aquatank 116 in order to allow water to run from the aquarium or aqua tank116 to the mechanical filtration device and sump by force of gravity,which will save energy and lower the cost of operation. If filter 101and sump 102 are not placed at elevations lower than aquarium 100, thena pump may be used to pump water from aquarium 100 to filter 101 andsump 102.

From sump 102, water flows to a number of other processing apparatuswhich further purify and condition the water. These apparatus include abio-filter 107; a protein skimmer 109; an oxytower 110; a denitrationsystem 112, a desulfator 111; an optional heater or chiller 114, foradjusting the temperature of the water; and a UV sterilizer 113, forsterilizing the water before it returns to aquarium or aqua tank 116.

As shown in FIG. 1, a portion of the water flows from the sump tobio-filter 107, then to protein skimmer 109, and then to oxytower 110.The remaining water flowing from the sump flows to denitration system112 and desulfator 111, and then to oxytower 110. The percentages ofwater flowing from the sump to bio-filter 107 and from the sump todenitration system 112 may be adjusted to achieve the desired waterconditions. For example, about 90% to about 99% of the water may flowfrom the sump to bio-filter 107, while about 1% to 10% may flow from thesump to denitration system 112. More preferably about 97% to about 99%of the water may flow from the sump to bio-filter 107, while about 1% toabout 3% may flow from the sump to denitration system 112.

From oxytower 110, the water may flow through an optional heater orchiller, in order to maintain the water in aquarium or aqua tank 116 atan acceptable temperature for the fish. Heaters and chillers are wellknown in the aqua culture art. The water then flows through UVsterilizer 113, which kills any microorganisms in the water, such asbacteria, which may be harmful to the fish, before flowing back to theaquarium. Such UV sterilizers are also well known in the art.

Bio-filter 107 uses aerobic bacteria processing to treat the water toreduce ammonia to nitrite and nitrite to nitrate. The water to betreated is flowed through a chamber which contains a support media onwhich the aerobic bacteria may colonize. A gas comprising oxygen isintroduced into the chamber to improve the efficiency of the aerobicbacteria process.

One embodiment of a bio-filter which may be used is illustrated in FIG.27. In this embodiment, bio-filter 107 comprises a tank 108. Preferablythe lower portion of which has a tapered shape to collect sediment whichsettles to the bottom, although it may have a flat bottom. For example,tank 108 may be in the shape of cylinder with a cone shaped bottom. Adrain 326 a and valve 326 b can be included in the bottom of tank 108,to allow sediment to be periodically removed. If desired, a clearsection of pipe 326 c may be employed to allow visual inspection of thedrain so that sediment buildup may be monitored. A lid 106 may be usedto cover the tank 108.

The chamber has an inlet 111 and an outlet 121 through which water canenter and exit the chamber. A screen 101 may be placed over the outletand inlet to avoid clogging and contain the media within the chamber.The height H1 of the outlet pipe 121 a will control the level of waterin the bio-filter 107.

Bio-filter 107 may be partially or completely filled with support media112, which acts as a substrate for the aerobic bacteria. The aerobicbacteria already exist in the water of the aquarium and will readilycolonize on the media. The media 112 may be any type of media that cansupport colonization of aerobic bacteria. While a media having anypractical size and shape may be used, media having a high surface areais preferred. For example, sand, crushed coral and other media havingrelatively high surface areas may be used. One preferred form of supportmedia is plastic, which may be in the form of small spheres or tubes,although any shape known in the art may be used. The plastic media islightweight and may float in the aquarium water. It does not clogeasily, and provides a large surface area for bacterial colonization.One example of such a plastic media is known as biofilm. Examples ofbiofilm which may be used include Kaldnes and Bee-Cell, which aremanufactured by Water Management Technologies, Inc. Other media likeBio-Chem stars from RENA may also be used.

A mixing eductor 653, is used to eject a gas comprising oxygen into thetank. The bubbles are well mixed with the water in the tank by mixingeductor 653, which comprising an inlet channel 653 a, a mixing chamber653 b, and a tubing 653 c. A pump 656 circulates water from bio-filter107 through pipe 658 to the inlet channel 653 a, where the water isforced through the mixing chamber 653 b and mixed with the gas fromtubing 653 c and additional water entrained by the mixing eductor fromthe bio-filter. Alternatively, the water going to eductor inlet channel653 a could be supplied from a source outside the bio-filter chamber,such as from the sump or the aquarium itself. Mixing eductor 653 and itsoperation are described above in more detail with reference to FIGS. 21a to 22 b.

In one embodiment, mixing eductor 653 may be supported inside bio-filter107 by a support 657, in the manner illustrated in FIGS. 28 a and 28 b.As shown in FIG. 28 b, the mixing chamber 653 b is supported by a plate657 c, so that the inlet cone of the mixing eductor is contained insidea small chamber composed of perforated plates, or screens, 657 a, thetop plate 657 c and a bottom plate 657 b. Water flowing through theperforated plates or screens 657 a is entrained into the inlet cone ofmixing chamber 653 c.

The aerobic bacteria exist and thrive in the water and will colonize onthe media within the bio-filter chamber as the system is operated. Thetype of aerobic bacteria utilized in bio-filter 107 may include, forexample, nitrosomonas and nitrobacter bacteria. These naturallyoccurring bacteria break down ammonia and nitrites in the water and formnitrates.

The flow rate through the bio-filter may be optimized to achieve thedesired water quality. For example, the flow rate through the bio-filtermay range from 1 to 30 times the volume of the aquarium per hour, andmore preferably from 3 to 10 times per hour.

The water from bio-filter 107 flows to protein skimmer 109. The purposeof the protein skimmer is to remove contaminants, such as undesirableorganic matter, otherwise known as dissolved organic compounds (DOC),from the water, as well as to increase the oxygen level of the water.Any protein skimmer known in the art may be used for this application.

One preferred embodiment employs a novel protein skimmer which utilizesa mixing eductor to introduce bubbles into the water. This novel proteinskimmer is described above in connection with FIGS. 20 a to 20 c.

The flow rate through the protein skimmer may be optimized to achievethe desired water quality. For example, the flow rate through thebio-filter may range from 1 to 30 times the volume of the aquarium perhour, and more preferably from 3 to 10 times per hour.

Water from protein skimmer 109 flows to oxytower 110, which utilizedalgae to remove phosphates, sulfates and nitrates from the water. Theoxytower may also add oxygen to the water. By oxygenating the water, thepH will remain more stable than water that is oxygen deficient. Further,the oxytower will also help to cool the water by evaporation. A detaileddiscussion of the oxytower is provided above in connection with FIGS. 18a to 19 b.

As discussed above, a portion of the water flowing from the sump isflowed to a denitration system 112, which is used to reduce nitrateconcentrations in the water. In order to manage nitrate levels in thewater, any denitration system known in the art may be employed.

In a preferred embodiment, the denitration system 112 is a Nitrafixsystem, as described herein above. Any of the Nitrafix systems describedabove could potentially be used. Preferably, the Nitrafix system usedwould comprise an optional filtration step 1, in which the water to betreated passes through a filter (not shown); an optional aerobicbacteria processing step 2 occurs; an anaerobic bacteria processing step3; and an optional step 4, wherein one or more calcium reactors areemployed for maintaining pH and adding calcium.

For large commercial applications, the denitration system 112 maypreferably employ the systems described in connection with FIG. 17above. For example, as an aerobic chamber 610, one or more denitrationchambers 620 and optionally one or more calcium chambers 630, could beused. For example, in one preferred embodiment, the aerobic chambercould be the chamber described in connection with FIG. 24; thedenitration chamber could be chosen from one of the chambers describedin connection with FIGS. 9 and 11; and either no calcium chamber, or oneor more calcium chambers, as described in connection with FIG. 25 may beemployed. In yet another embodiment, only one or more denitrationchambers 620 are employed, with no aerobic chamber, and with either nocalcium chamber, or one or more calcium chambers.

Alternatively, the denitration system 112 may preferably employ theNitrafix system described in connection with FIGS. 2 to 6 above. Forexample, an aerobic chamber 110, a denitration chamber 120 could beemployed, either with no calcium chamber or with one or more calciumchambers. In yet another embodiment, a denitration chamber 120 could beemployed, either with no calcium chamber or with one or more calciumchambers. If calcium is used, a single source of calcium may beemployed, or multiple sources.

The chambers of the Nitrafix system may be arranged in a singlecontainer, as described in FIGS. 8 a to 8 c or FIG. 15.

A further process step, which may be added after the denitration system112 described herein, can be used to reduce sulfate concentrations. Asdescribed above, the denitration process of the systems of the presentinvention results in increased levels of sulfates in the water.Additionally, there is the possibility that undesirable amounts ofhydrogen sulfide may also be produced at certain times, such as atstartup, after the denitration chamber has been shut down for a periodof time. Consequently, it may be desirable in some aqua culture systemsto reduce the level of sulfates and/or hydrogen sulfide. Accordingly,the novel method and desulfator apparatus, described above withreference to FIGS. 23 a to 23 f, may be employed for reducing sulfateand hydrogen sulfide concentrations in the water. Alternatively, anysystem known in the art for reducing sulfate in the water may beemployed.

Referring back to FIG. 26, a monitoring system 115 may be used tomonitor the properties of the aqua tank water, such as temperature, pH,salinity, dissolved oxygen, ORP, flow, pressure, levels and powerfailure of the water. The parameters of the water treating system ofFIG. 1 may then be controlled based on the feed back from monitoringsystem 115. For example, the ORP, which is a measure of waterconductivity, may be used to control ozone levels in the proteinskimmer, since ozone cleans the water and thus affects the waterconductivity.

Additional water may occasionally need to be added to the system of FIG.26. If so, the water may be supplied, for example, by a reverse osmosisunit 103, which may be used to filter city water and make it safe forthe fish.

Water may be pumped to bio-filter 107 and the denitration chamber 112using a pump 104, as shown in FIG. 27. The bio-filter 107 anddenitration chamber 112 may be placed at higher elevations then theother chambers in the system, including the protein skimmer, theoxytower and the desulfator, so that the water may then run by force ofgravity through these chambers and back to aquarium 100, thus savingpower. Alternatively, a separate pump may be used to pump water to theother chambers, such as the protein skimmer, the oxytower and thedesulfater. Pump 104 is preferably a type of pump which consumesrelatively low energy, such as a flow pump. Pumps 106 and 108, as shownin FIG. 26, may be, for example, pressure pumps. Other types of pumpsknown in the art may also be used for pumps 104, 106 and 108.

The system of FIG. 26 may be modified according to the desired waterquality to be obtained and the cost of the system. For example, in oneembodiment, desulfator 111 is not employed in the system of FIG. 26, sothat the water flows directly from denitration chamber 112 to oxytower110. In yet another embodiment, protein skimmer 109 is not employed, sothat the water from bio-filter 107 flows directly to oxytower 110. Inyet another embodiment, oxytower 110 is omitted, so that water flowsfrom bio-filter 107 and either the desulfator 111, or the denitrationchamber 112 (if the desulfator is not employed), to the protein skimmer109, and then from the protein skimmer 109 to aquarium or aqua tank 116,via the optional chiller/heater and UV sterilizer. In still anotherembodiment, the order of the protein skimmer and oxytower are reversed,so that water flows from the bio-filter 107 to the oxytower 110 and thento the protein skimmer 109, and then down to the aquarium via theoptional chiller/heater and UV sterilizer. In this last embodiment,water may flow from either the desulfator 111, or the denitrationchamber 112 (if the desulfator is not used) to either the proteinskimmer 109 or the oxytower 110. In yet another embodiment, the proteinskimmer, oxytower and desulfator are all omitted, so that water flowsfrom the denitration chamber 112 to the bio-filter 107, and from thebio-filter 107 to the aquarium, via the optional chiller/heater and UVsterilizer. In yet another embodiment, the flow through the oxytower andskimmer may be in parallel so that water flows from the bio-filter 107to the skimmer and the oxytower at the same time and then down to theaquarium via the optional chiller/heater and UV sterilizer.

In yet another embodiment, the flow of water from the bio-filter outletmay be split, so that only a portion of the water from the outlet ofbio-filter 107 flows to the skimmer 109, while the remaining portionflows to either the chiller/heater and UV sterilizer or directly to theaquarium. For example, ⅓ of the water from the bio-filter may flow tothe protein skimmer, while ⅔ of the flow goes to the aquarium via theoptional chiller/heater and UV sterilizer.

In all the embodiments listed herein, both the UV sterilizer 113 and thechiller or heater 114 may be omitted. Additionally, a sump need not beemployed, but instead the water may be pumped and returned directly tothe aquarium tank.

Other flow arrangements are also contemplated. For example, each of thechambers, including denitration chamber 112, desulfator 111, oxytower110, protein skimmer 109 and bio-filter 107, may be used separately, sothat the water from either the sump or the aquarium may be floweddirectly to each chamber, and then returned directly back to either thesump or the aquarium. Still other flow arrangements and configurationsare possible, as may be appreciated by one of ordinary skill in the art.

The system of FIG. 26 may be assembled in a compact manner on a singlesupport, known as a “skid.” This would allow the system to bemanufactured and assembled off-site and then shipped to the aqua tanklocation ready to be used. Such an integrated system would also likelycost less than a system built on site.

EXAMPLE

A biological system according to the present invention which was similarto the embodiment illustrated in FIG. 8 was used to filter a 500 gallonaquarium containing relatively large numbers of fish. The tank initiallyhad a nitrate concentration of approximately 50 ppm. After three weeksof conditioning the water with the above mentioned biological system,the nitrate content of the aquarium was reduced to a safe level, under 5ppm NO₃ ⁻, and was maintained at about that level for several months.

With respect to the flow rate of water through the system of the presentinvention, flow rates within the range of 5 to 7 gph were found to beworkable for a denitration chamber made according to the embodimentshown in FIG. 14, for aquariums ranging in size from 250 to 500. Flowrates in the range of 3 to 5 gph were found to be acceptable fordenitration chambers of that type where the aquariums being serviced arewithin the range of 50 to 500 gallons. When the system is originallyplaced on-line, a flow can be adjusted through the valve system. One wayof adjusting the flow is to place a glass of a given volume at theoutlet so that the flow can be measured and adjusted, until the desiredflow rate is achieved. In addition, if the nitrate level is greater thandesired, such as 5 ppm after the system has operated for 30-90 days, theflow rate can be adjusted at a higher level, to achieve the desirednitrate level.

The biological systems disclosed in this application can be used forboth salt and fresh water aquariums, as well as brackish wateraquariums. The systems may be used for both cold water and heatedaquariums. Heating the aquarium water to a temperature range whichallows the bacteria to be efficient before it enters the biologicalsystems of the present invention may provide improved results. Forexample, if Thiobacillus denitrificans are employed, the water in thechamber should preferably have a temperature ranging from 25 to 30degrees Celsius.

While the methods, devices, and systems of the present invention havebeen disclosed for use in treating water for aquariums, all or aspectsof the disclosed inventions can also be used in other applications wherewater must be treated. For example, the denitration methods and systemscan be used, along with other apparati and methods, in fish farms, hogfarms, and other applications where high levels of nitrates are producedand need to be removed and/or treated.

While certain materials may have been disclosed for construction of thevarious chambers, piping and other parts of the systems disclosedherein, it will readily be recognized that other materials known in theart may also be used.

While the invention has been disclosed herein in connection with certainembodiments and detailed descriptions, it will be clear to one skilledin the art that modifications or variations of such details can be madewithout deviating from the general concept of the invention. Thus theinvention is to be limited by the claims, and not by the embodiments anddetailed description provided above.

1. A system for conditioning water in a contained environment forholding aquatic life, the system comprising a first chamber in fluidcommunication with the contained environment, the first chambercontaining aerobic bacteria for substantially reducing the oxygenconcentration of the water flowing from the contained environment and afirst media to sustain said aerobic bacteria for an extended period oftime and in a sufficient amount to substantially reduce the oxygenconcentration in the water, as the water flows through the firstchamber; and a second chamber in fluid communication with both the firstchamber and the contained environment in a manner which allows the waterhaving a substantially reduced oxygen concentration to flow from thefirst chamber to the second chamber and the water leaving the secondchamber to flow back to the contained environment, the second chambercontaining anaerobic bacteria for substantially reducing the levels ofnitrates in the water and a second media comprising a sufficient amountof sulfur to sustain said anaerobic bacteria for an extended period oftime and in a sufficient amount to substantially reduce the level ofnitrates in the water, as the water flows through the second chamber. 2.The system of claim 1 wherein the anaerobic bacteria compriseThiobacilus denitrificans bacteria.
 3. The system of claim 2 wherein theaerobic bacteria comprise at least one bacteria chosen from nitrosomonasand nitrobacter bacteria.
 4. The system of claim 1 wherein the anaerobicbacteria comprise at least one bacteria chosen from Thiobadilusdenitrificans, Thiobacillus versutus, Thiobacillus thyasiris,Thiosphaera pantotropha, Paracoccus denitrificans, and Thiomicrospiradenitrificans.
 5. The system of claim 1, wherein the structure of thesecond chamber is opaque and designed to minimize the application of anylight to the anaerobic bacteria in the second chamber.
 6. The system ofclaim 1, wherein a conduit provides the fluid communication between thecontained environment and the first chamber, at least a portion of theconduit being transparent so as to allow observation of water flowinginto the system, and a gate valve associated with the conduit allows foradjusting the flow rate of water through the conduit.
 7. The system ofclaim 1, wherein a conduit provides the fluid communication between thesecond chamber and the contained environment, at least a portion of theconduit being transparent so as to allow observation of the flow ofwater in the conduit.
 8. The system of claim 1, further comprising athird chamber in fluid communication with both the second chamber andthe contained environment in a manner which allows water to flow fromthe second chamber to the third chamber before returning to thecontained environment, wherein the third chamber contains a firstcalcium source.
 9. The system of claim 8, further comprising a fourthchamber in fluid communication with both the third chamber and thecontained environment in a manner which allows water to flow from thethird chamber to the fourth chamber before returning to the containedenvironment, wherein the fourth chamber contains a second calciumsource.
 10. The system of claim 9, wherein said first, second, third andfourth chambers are contained in a single container, the containerhaving an inlet and an outlet allowing fluid communication with thecontained environment and the chambers in the container.
 11. The systemof claim 10, wherein the container is a box-shaped container having foursides, a top and a bottom, the container is divided into four volumes byvertical dividing walls to form said first, second, third and fourthchambers, and openings are positioned in said dividing walls to allowwater to flow from one chamber to the next.
 12. The system of claim 10,wherein each of said first, second, third and fourth chambers is dividedinto an upper section, a middle section, and a lower section, by firstand second perforated shelves positioned within each of the chambers, sothat said first shelf is positioned horizontally within the chambers toseparate the upper section from the middle section, and the second shelfis positioned horizontally within the chamber and below the first shelfso as to separate the middle section from the lower section; and furtherwherein the upper section of each chamber contains carbon, the middlesection of each of said first, second, third and fourth chambersrespectively contains the first media, the second media, the firstcalcium source and the second calcium source, and the lower section ofeach of said first, second, third and fourth chambers remainssubstantially empty except for the flow of water therethrough.
 13. Thesystem of claim 10, wherein the inlet and outlet of the container andthe openings in the dividing walls are positioned so that water iscapable of entering the container near the top of the middle section ofthe first chamber and flowing down through the media in the firstchamber and into the lower section of the second chamber throughopenings in a dividing wall separating said first and second chambers,then flowing upward through the media in the second chamber and into themiddle section of the third chamber through openings formed in adividing wall separating the second and third chambers, then flowingdown through the media in the third chamber and into the lower sectionof the fourth chamber through openings in a dividing wall separating thethird and fourth chambers, then flowing upward through the media in thefourth chamber and exiting the container through the outlet.
 14. Thesystem of claim 1 further comprising a protein skimmer in fluidcommunication with the second chamber and the contained environment in amanner which allows the water to flow from the second chamber to theprotein skimmer and the water leaving the protein skimmer to flow backto the contained environment.
 15. The system of claim 14 wherein theprotein skimmer mixes a gas including oxygen with water in the proteinskimmer using a mixing eductor.
 16. The system of claim 14 wherein theprotein skimmer includes an enclosure for accepting a flow of water, amixing eductor within the enclosure, and a pump for introducing a forcedflow of water to the mixing eductor, the mixing eductor including afirst flow path for accepting the forced flow of water from the pump, asecond flow path for entraining water from the enclosure of the proteinskimmer, and a third flow path for accepting a flow of gas includingoxygen from outside the enclosure, the mixing eductor in operationmixing the forced flow of water, the entrained water and the gas withinthe enclosure.
 17. The system of claim 1 further comprising an oxytowerin fluid communication with the second chamber and the containedenvironment in a manner which allows the water to flow from the secondchamber to the oxytower and the water leaving the oxytower to flow backto the contained environment.
 18. The system of claim 17, wherein theoxytower comprises an enclosure for accepting a flow of water, theenclosure having side walls that slope inward at an angle θ_(oxy) fromvertical; and wherein a third media is placed on the inner surface ofthe sidewalls and serves as support for the growth of algae in theoxytower, and further wherein the flow of water flows down the sidewalls while contacting the algae in a manner which allows the algae toeffectively remove contaminants from the water and raise the pH of thewater.
 19. The system of claim 1 further comprising a desulfator influid communication with the second chamber and the containedenvironment in a manner which allows the water to flow from the secondchamber to the desulfator and the water leaving the desulfator to flowback to the contained environment.
 20. The system of claim 19 whereinthe desulfator includes an enclosure for accepting a flow of water,wherein the enclosure contains a third media on which anaerobicphotosynthetic bacteria are supported, and the water flows through theenclosure while contacting the third media in a manner which effectivelyreduces sulfate levels.
 21. The system of claim 20, wherein theanaerobic photosynthetic bacteria comprise at least one bacteria chosenfrom Chromatium vinossum, Thiospirillum jenense, Rhodospirilum rubrum,Rhodobacter sphaeroides, Chlorobium limicola, and Prosthecochlorisaestuarii.
 22. The system of claim 1 wherein the second media iscomprised of at least 50% sulfur by weight.
 23. The system of claim 1wherein the second media is comprised of at least 75% sulfur by weight.24. The system of claim 1 wherein the second media is comprised of atleast 90% sulfur by weight.
 25. The system of claim 1 wherein the secondmedia is comprised of between about 99% to about 100% sulfur by weight.26. A system for conditioning water in a contained environment forholding aquatic life, wherein the system is contained in a singlecontainer partitioned into chambers by perforated dividing wallsarranged inside the container, the system comprising a first chamberhaving an inlet in fluid communication with the contained environment,for accepting a flow of water from the contained environment, the firstchamber containing aerobic bacteria for substantially reducing theoxygen concentration of the water flowing from the contained environmentand a first media to sustain said aerobic bacteria for an extendedperiod of time and in a sufficient amount to substantially reduce theoxygen concentration in the water, as the water flows through the firstchamber; a second chamber in fluid communication with the first chamber,wherein said second chamber contains anaerobic bacteria forsubstantially reducing the levels of nitrates in the water, and a secondmedia comprising a sufficient amount of sulfur to sustain said anaerobicbacteria for an extended period of time and in a sufficient amount tosubstantially reduce the level of nitrates in the water, as the waterflows through the second chamber; a third chamber in fluid communicationwith the second chamber, wherein the third chamber contains a calciumsource; and a fourth chamber in fluid communication with the thirdchamber, the fourth chamber having an outlet for allowing the flow ofwater back to the contained environment; wherein the chambers arearranged inside the container in a manner which allows for waterentering the system through said inlet in the first chamber to flowthrough perforations in the dividing walls to the second, third andfourth chambers, in that order, and thereafter to exit the systemthrough the outlet in the fourth chamber.
 27. The system of claim 26,wherein the outlet comprises an outlet pipe which extends verticallydown into the fourth chamber, and wherein the system further comprises adevice for forcing air into the outlet pipe so that the air will rise upthrough the outlet pipe in a manner which will force water out of thesystem.
 28. The system of claim 27, wherein the calcium source comprisesat least two different sources of calcium.
 29. The system of claim 26wherein the anaerobic bacteria comprise Thiobacilus denitrificansbacteria.
 30. The system of claim 29 wherein the aerobic bacteriacomprise at least one bacteria chosen from nitrosomonas and nitrobacterbacteria.
 31. The system of claim 26 wherein the anaerobic bacteriacomprise at least one bacteria chosen from Thiobadilus denitrificans,Thiobacillus versutus, Thiobacillus thyasiris, Thiosphaera pantotropha,Paracoccus denitrificans, and Thiomicrospira denitrificans.
 32. A systemfor conditioning water in a contained environment comprising: acontainer sized and designed to hold aquatic life; a bio-filter in fluidcommunication with said container, wherein the bio-filter reducesammonia to nitrite and nitrite to nitrate; and a denitration system influid communication with said container, wherein the denitration systemincludes one or more chambers containing anaerobic bacteria and furthercontaining media comprising a sufficient amount of sulfur to sustainsaid anaerobic bacteria for an extended period of time and in asufficient amount to substantially reduce the nitrate content in thewater, as the water flows through the one or more chambers, and whereinthe water exiting the denitration system flows back to said container.33. The system of claim 32, wherein the denitration system furthercomprises a chamber containing aerobic bacteria which reduces the oxygenconcentration of the water in the second stream before the water isintroduced to the one or more chambers containing anaerobic bacteria.34. The system of claim 32, wherein the denitration system employs oneor more chambers containing calcium for adjusting the pH of the water asit exits the chamber containing anaerobic bacteria.
 35. The system ofclaim 32 wherein the media is comprised of at least 50% sulfur byweight.
 36. The system of claim 32 wherein the media is comprised of atleast 75% sulfur by weight.
 37. The system of claim 32 wherein the mediais comprised of at least 90% sulfur by weight.
 38. The system of claim32 wherein the media is comprised of between about 99% to about 100%sulfur by weight.
 39. A system for conditioning water in a containedenvironment comprising: a bio-filter in fluid communication with thecontained environment, wherein the bio-filter reduces ammonia to nitriteand nitrite to nitrate; a denitration system in fluid communication withthe contained environment, wherein the denitration system includes oneor more chambers containing anaerobic bacteria and further containingmedia comprising a sufficient amount of sulfur to sustain said anaerobicbacteria for an extended period of time and in a sufficient amount tosubstantially reduce the nitrate content in the water, as the waterflows through the one or more chambers, and an oxytower in fluidcommunication with the bio-filter, denitration system, and containedenvironment such that water exiting the bio-filter and dentirationsystem will flow into the oxytower, and water exiting the oxytower willflow back to the contained environment.
 40. The system of claim 39wherein the oxytower comprises an enclosure for accepting a flow ofwater, the enclosure having side walls that slope inward at an angleθ_(oxy) from vertical; and wherein a media is placed on the innersurface of the sidewalls and serves as support for the growth of algaein the oxytower, and further wherein the flow of water flows down theside walls while contacting the algae in a manner which allows the algaeto effectively remove contaminants from the water and raise the pH ofthe water.
 41. The system of claim 39 further comprising a desulfator influid communication with the denitration system and the oxytower, sothat water exiting the denitration system will flow into the desulfator,and water exiting the desulfator will flow into the oxytower.
 42. Thesystem of claim 41 wherein the desulfator comprises an enclosure foraccepting a flow of water, wherein the enclosure contains media on whichanaerobic photosynthetic bacteria are supported, and further wherein thewater flows through the enclosure while contacting the media in a mannerwhich effectively reduces sulfate levels.
 43. The system of claim 39further comprising a protein skimmer in fluid communication with thebiofilter and the oxytower, such that water exiting the biofilter willflow into the protein skimmer, and water exiting the protein skimmerwill flow into the oxytower.
 44. The system of claim 43 wherein theprotein skimmer comprises an enclosure for accepting a flow of water, amixing eductor within the enclosure, and a pump for introducing a forcedflow of water to the mixing eductor, the mixing eductor including afirst flow path for accepting the forced flow of water from the pump, asecond flow path for entraining water from the enclosure of the proteinskimmer, and a third flow path for accepting a flow of gas includingoxygen from outside the enclosure, the mixing eductor in operationmixing the forced flow of water, the entrained water and the gas withinthe enclosure.
 45. The system of claim 39 wherein said containedenvironment is designed and sized for holding aquatic life.
 46. A systemfor conditioning water in a contained environment comprising: abio-filter in fluid communication with the contained environment,wherein the bio-filter reduces ammonia to nitrite and nitrite tonitrate; a denitration system in fluid communication with the containedenvironment, wherein the denitration system includes one or morechambers containing anaerobic bacteria and further containing mediacomprising a sufficient amount of sulfur to sustain said anaerobicbacteria for an extended period of time and in a sufficient amount tosubstantially reduce the nitrate content in the water, as the waterflows through the one or more chambers, and a protein skimmer in fluidcommunication with the bio-filter, denitration system, and containedenvironment, such that water exiting the bio-filter and denitrationsystem will flow into the protein skimmer, and water exiting the proteinskimmer will flow back to the contained environment.
 47. The system ofclaim 46 wherein the protein skimmer comprises an enclosure foraccepting a flow of water, a mixing eductor within the enclosure, and apump for introducing a forced flow of water to the mixing eductor, themixing eductor including a first flow path for accepting the forced flowof water from the pump, a second flow path for entraining water from theenclosure of the protein skimmer, and a third flow path for accepting aflow of gas including oxygen from outside the enclosure, the mixingeductor in operation mixing the forced flow of water, the entrainedwater and the gas within the enclosure.
 48. The system of claim 46further comprising a desulfator in fluid communication with thedenitration system and the protein skimmer, so that water exiting thedenitration system will flow into the desulfator, and water exiting thedesulfator will flow into the protein skimmer.
 49. The system of claim48 wherein the desulfator comprises an enclosure for accepting a flow ofwater, wherein the enclosure contains media on which anaerobicphotosynthetic bacteria are supported, and further wherein the waterflows through the enclosure while contacting the media in a manner whicheffectively reduces sulfate levels.
 50. The system of claim 46 furthercomprising an oxytower in fluid communication with the biofilter and theprotein skimmer, such that water exiting the biofilter will flow intothe oxytower, and water exiting the oxytower will flow into the proteinskimmer.
 51. The system of claim 50 wherein the oxytower comprises anenclosure for accepting a flow of water, the enclosure having side wallsthat slope inward at an angle θ_(oxy) from vertical; and wherein a mediais placed on the inner surface of the sidewalls and serves as supportfor the growth of algae in the oxytower, and further wherein the flow ofwater flows down the side walls while contacting the algae in a mannerwhich allows the algae to effectively remove contaminants from the waterand raise the pH of the water.
 52. The system of claim 46 wherein saidcontained environment is designed and sized for holding aquatic life.53. A system for conditioning water comprising: a contained environmentsized and designed for holding aquatic life; and a denitration system influid communication with the contained environment wherein thedenitration system includes two or more containers connected in series,and wherein each container comprises: a first chamber having an inletfor accepting a flow of water and containing aerobic bacteria forsubstantially reducing the oxygen concentration of the water and a firstmedia to sustain said aerobic bacteria for an extended period of timeand in a sufficient amount to substantially reduce the oxygenconcentration in the water, as the water flows through the firstchamber; a second chamber in fluid communication with the first chamber,wherein said second chamber contains anaerobic bacteria forsubstantially reducing the levels of nitrates in the water, and a secondmedia comprising a sufficient amount of sulfur to sustain said anaerobicbacteria for an extended period of time and in a sufficient amount tosubstantially reduce the level of nitrates in the water, as the waterflows through the second chamber; a third chamber in fluid communicationwith the second chamber, wherein the third chamber contains a calciumsource; and a fourth chamber in fluid communication with the thirdchamber, the fourth chamber having an outlet for allowing the flow ofwater out of the container; wherein the chambers are arranged inside thecontainer in a manner which allows for water entering the system throughsaid inlet in the first chamber to flow to the second, third and fourthchambers, in that order, and thereafter to exit the container throughthe outlet in the fourth chamber; wherein the two or more containers arein fluid communication with each other and the contained environmentsuch that water exiting the contained environment flows into said firstcontainer through said inlet in the first chamber, and water exiting thefourth chamber of the first container flows to the inlet of the nextsuccessive container, or in the case of the last of the two or morecontainers, back to the contained environment.
 54. The system of claim53, wherein the first container of the two or more sequential containersof the denitration system comprises a first chamber containing aerobicbacteria for substantially reducing the oxygen concentration of thewater flowing from the contained environment and a first media tosustain said aerobic bacteria for an extended period of time and in asufficient amount to substantially reduce the oxygen concentration inthe water, as the water flows through the first chamber.
 55. The systemof claim 54, wherein the second container and any subsequent containerscomprise: a first and second chamber in fluid communication, whereinsaid chambers contain anaerobic bacteria for substantially reducing thelevels of nitrates in the water, and a second media comprising asufficient amount of sulfur to sustain said anaerobic bacteria for anextended period of time and in a sufficient amount to substantiallyreduce the level of nitrates in the water, as the water flows throughthe first and second chambers in that order.
 56. The system of claim 53further comprising an oxytower in fluid communication with thedenitration system and contained environment such that water exiting thedentiration system will flow into the oxytower, and water exiting theoxytower will flow back to the contained environment.
 57. The system ofclaim 53 further comprising a protein skimmer in fluid communicationwith the denitration system and contained environment such that waterexiting the dentiration system will flow into the protein skimmer, andwater exiting the protein skimmer will flow back to the containedenvironment.